a hand / a handle, grip / a paw, foreleg / a way of acting, means / (board games) a move, play

黴菌: germs, something like bacteria that is harmful to the body

to wash

to spread, to extend

媒体: medium

(dialectal, Kyūshū) sentence-ending particle indicating assertion

売店: stand or small shop

(Saga) very

(slang) amazing

(idiomatic) go straight, quit a shady business, wash one's hands of some work or lifestyle which is less than respectable / (idiomatic, neologism) quit a business (regardless of its respectability)