Basic Cleansing and Protection Rites
In the end it comes down to three major items: salt, sage, and showers. If you use these three things you should be able to cleanse almost anything and be ready for a ritual. Many of these items are also good for protection.
Salt is both a protective barrier as well as a cleansing item. Belief in the supernatural properties of salt is part of why we use it to preserve foods. Or perhaps it's the fact that it does kill some pathogens/molds so we thought it was magical? Either way, for supernatural reasons any salt works, though less processed salts are usually better than common table salt.
To cleanse items: bury items that shouldn't get wet in salt. For example, paper. Leave it for at least a day. If the item doesn't feel purified yet, re-bury it and wait longer. If an item is to be used for a day-aligned entity, leaving the salt in a sunny place like a windowsill can help. Take it away from there once the sun sets. If the item is to be used towards someone night-aligned, do the same thing but only at night. Ideally take it back somewhere safe before the moon is gone from the sky. Not sure on alignment? Leave the salt indoors away from windows and doors.
To cleanse yourself or "quick clean" items: rub them with salt. Don't rub hard as salt can be scratchy which can cause damage! Use food-grade salt if rubbing it on yourself. Be careful between your legs- you might want to do that one area with water only. Discard all used salt. If using salt on yourself, follow it up with a shower.
To create a protective barrier: Take salt that is unused. Pour it in a circle around any area that needs protection. Salt can also be poured across doorways and windowsills to easily protect a room. Do not miss any doors or windows or the barrier will have holes in it! Leave the salt there as long as you feel you need it. Replace old salt with new salt if the barrier feels weak. Discard used salt.
Water is a popular cleansing item in most faiths and for practical use as well. It has been used as a barrier as well, but is only effective in some circumstances. I'd suggest salt and sage over water as a barrier due to difficulty of use. Water is pretty easy for cleansing, though.
To cleanse items: Place waterproof items in a bowl that has either been salt-cleaned or quick-cleaned with water. Allow them to rest at least a day. The same day/night trick works with water as well.
To "quick cleanse" items: Hold waterproof items under flowing water. Yes, tap water works. Slowly turn the item under the water to assure water flows everywhere. Do not splash or keep any water that comes off the item. Keep doing this until it feels cleansed.
To cleanse yourself: Rub your body down with salt. Turn on the shower and step in with a clear head. Keep your mind as clear as possible. If you are doing this to cleanse yourself before trying to work with an entity, you may think of that entity as you bathe. Don't use soap, just use water. Let the water flow over you and do not splash it! Let the water flow over you and do not splash it! The water needs to stay away from you, flowing down the drain as it cleanses you. Rinse your mouth out, and spit it away from you down the drain. Rinse out the tub and pat yourself dry with a towel when done. You may now use sage if you need further cleansing.
Sage (or other herbs)
Sage is a good all-purpose supernatural cleansing herb. This said, certain entities may ask for other plants such as lavender or tobacco. Most plants can be used in the same way as sage. For ease of reading, I'll just call all ritual cleansing herbs "sage". Substitute whatever you're actually using here. Know if the plant is toxic before use!
Do NOT bury items in herbs! This is done to make offerings, create charms, and do other rites. It's not used for cleansing. Also, rubbing items with sage is not used for cleansing. It's used for blessing and other rites after you're done cleansing. There is only one real way to use sage for cleansing: smoke.
How to burn sage: This is best done outdoors if you're doing a bunch of cleansing due to all the smoke. Smaller amounts may be used indoors with good ventilation. Keep a fire extinguisher on hand and use common sense to stay safe.
Get some whole plant dried sage. You can buy fresh sage at a farmer's market or grocery store and hang it up to dry if you like. Tie your sage into a tight bundle with cotton cord. You can buy "smudge sticks" ready to go like this. If you buy a smudge stick, avoid scented sticks. Only buy smudge sticks made of the herbs you plan to use.
Set your smudge stick / herb bundle on fire. I suggest holding the leafy end over a candle to help this. Blow out the flame once the end is 100% on fire. Then let it smolder over something fireproof like a plate. You can prop it up at an angle using something smaller and fireproof, like an incense burner. This will help it burn. A fan on low or blowing on the sage can also be helpful if the sage is being stubborn, but beware of embers!
To cleanse items: Hold your item above the smoke. Turn it over and over in the smoke until it feels cleansed. This is the only method, there is no "quick cleanse".
To Cleanse yourself: This can be done after a salt and shower for a thorough cleanse. It can also be done on it's own for a "quick cleanse".
Take your lit sage and hold it in your hand. Pass it under your body parts to let the smoke flow up and over them. Start at the limbs, then do your chest and head. Lastly, put the sage on the burning plate on the ground. Stand over it to let the smoke flow over your thighs, genitals and underside. Repeat any areas that feel like they need it.
To cleanse a room: Take your sage and move it around the room perimeter slowly. Let the smoke rise to the ceiling. Then let the sage rest in the center of the room until the room has a "sage smoke" smell. A small haze of smoke is fine. Snuff out the sage. If the fire alarm goes off you burned too much. Snuff out the sage and wave a towel under the alarm until it stops beeping.
Using sage to protect a room: If you want to create a protected area with sage and salt, burn the sage first. Add the salt barrier as you let the sage finish out in the middle of the room. This gives anything inside the room a chance to escape before you seal all exits. The steps are otherwise the same as already mentioned for protecting an area with salt and cleansing a room with sage.
Sage tends to leave a protective barrier behind on anything it cleanses. As long as you don't wash the item off with water or salt this barrier will last awhile. This is because sage smoke contains sage resin which coats items naturally. This can also make things sticky. If you don't like the stickiness, you may want to use older dried sage (it's less resinous) or refrain from using sage.
Can I double-up?
Yes! It is perfectly fine to use more than one cleansing method. Do it in this order: Salt, Water, Sage.
Stage 1: salt. Salt is a good base and an excellent "wall"
Stage 2: Water. Water rinses away salt and anything the salt trapped. Skip the water if the item isn't waterproof and instead brush it clean of all salt. Discard any salt stuck to the item or leftover from stage 1.
Stage 3: Sage. Sage is a finishing touch that leaves a light protective residue as it cleanses. If you need to re-cleanse an item, repeat the same order of steps.