Simply wash, rinse, and blot to see if there’s any makeup remaining. When they’re clean, hang them upside down to dry so water doesn’t collect in the handle
A lot of these use simple, cheap ingredients you probably already have. Just a reminder, though: NEVER EVER mix ammonia with anything that has or you think might have bleach in it, as this produces a poisonous gas. When using ammonia, it’s best to mix it with water only. Err on the side of caution and don’t play chemist. Any of these materials can also irritate skin and eyes, so wear gloves and try not to touch your face, too.