Is this a good idea? I’ve never done it but seen many photos and films (The Doors, Paul McCartney) and read that Bjork recorded live in a club’s toilets. It intrigues me but I imagine the reverberation being too much.
I think they experimented but not necessarily used. I’ve seen the scene in The Doors film but it looks more about separation over the reverb sound of the space but not sure if that was real life either.
That said, this is the fun part of recording. Try it and see what it sounds like to you. All bathrooms will have different sounds, yes some will be very live with all the hard surfaces. But you need to take into account, the mics and outboard you’ll use, the sound you’re after and how it mixes in. Try is a a double track and have it lower than the other vocal track to use as an effect. Have fun and experiment with it.????