The players avoided this trap, by just peeking into the room and deciding it was boring. So no green slime showers, and no out-of-the-box ideas on fun things they could do with a shower that shoots green slime. Not that it was ever really likely that they would decide to take a shower. One design principle that I'm sticking to (probably foolishly) is to not re-use unencountered traps & other special features later on in the dungeon. Once I've stuck it in a room, I'm leaving it there - if it is never seen, so be it. I want to put some creative pressure on myself with this campaign.
This area contains showers and toilets. There are cracked tiles on the floor (with the same white material as the walls underneath the tiles), but the porcelain toilet bowls and protonium-metal showerheads and faucets are still intact. There are some holes in the wall where sinks and counters used to be, but those are gone. If investigated, the toilet bowls will be found to contain a green slime (AC always hit, HD 2*, hp 13, #AT 1, D dissolve, MV (1’), Save F 1, ML 12). The same slime is living in the protonium-metal pipes. It cannot surge upwards from the toilet bowls, but if the showers are turned on, it will spray down on whoever has turned the faucet.