to the Japan unfucker (hi, i live here, too!) perhaps try kabi killer (カビキラー）or something? idk i haven't had to do crazy heavy-duty cleaning here, but you should prob have some of that stuff on hand anyway. what i used back home (US) for tough stuff was SOS pads. and idk if they have that sort of thing, i feel like i've definitely seen something similar to steel wool. might help?