If you are able to leave your tank empty to air for 24 hours: Use a mild (and I do mean MILD people, very very mild) bleach dilution to wash and sterilize the tank. Rinse it very well with water and then rinse again with vinegar to neutralize any traces of bleach. Allow the tank to air out for 24 hours. If you are unable to leave the tank empty, use vinegar only and rinse well.
Sand should be checked every day for stray bits of food that will mold. Once per month, remove the sand and place it on a baking sheet in the oven for 30 minutes on 350F. Allow it to cool completely before returning it to the tank. If you choose to buy new sand each time, it should still be baked to ensure it’s sterile. Forest bedding substrates should be thrown out and replaced as often as needed. Be diligent about picking out stray bits of food each day to prevent mold.
Empty shells and other heat resistant items can be boiled monthly. Wood logs, branches and coco huts can also be baked but be vigilant and don’t leave them unattended. Netting can be soaked in a vinegar and water mix to clean it. You should do this with all newly purchased netting. Allow it to soak over night, then change the water out and soak it again. If the water is clear after a second soak, you should be fine. Otherwise, continue changing the water until it’s clear.
Wash food and water dishes frequently.
Avoid using soap or chemicals on anything that your hermit crabs will come in contact with.