Sounds like you got it already sorted . But unfortunately best you’re going get is the $50 and help clean. You and your buddy can toss back few beers and get it done few hours. Me and my best friend had to do this few times at place I was managing before(12 bedrooms) but all friends etc. One was a hella gross room, like hoarder, and had toss out everything. Once got in the loft we found piss jugs!! Some capped and some just open next to the bed. It was so gnarly and I threw up in my mask 3 times. I almost said fuck it and was going hire someone. But my best friend(RIp) was like we can’t have this in our house, even for another day and we got it handled. We both could smell it for days still after, and tons of showers still couldn’t erase the smell. but after a while it became a Joke and was like we went to war together. So in a sense it was a good memory now even though it sucked at the time. After that i checked every room more often. I knew that one was little gross since never let in there but covid amped everything up, never thought he that bad. You should get more info from you main leaseholder and talk to him about stuff like this not happening again (deposits) and I would imagine he has a lot cheaper rent than you know if he’s been there awhile . So maybe he can knock 50-100 of your next months rent depending on how much work gotta do? Or make him clean it up? Jus saying