I use only a bathroom sink for washing snake bowls (or less often, my laundry sink for washing really large bowls or hides). If they happen to poo in their
water bowl, that gets dumped in my flower bed or toilet. I wouldn't use my kitchen sink for this (ever) but I see no issue with using a bathroom sink. It's
likely that our snakes have as much to worry about from OUR germs as we do from theirs. (not saying they WILL "worry") Objects contaminated with fecal
material of any species do not belong in the kitchen, IMO....not because you aren't washing & disinfecting it, but because tiny splashes happen & are likely
to go unnoticed on surrounding surfaces. When it comes to water bowls that do not contain any visible fecal material, the fact remains that they have been
in the cage with a snake that can easily have touched both.
Now that's what I personally do, but anytime you have room-mates, you're going to have to be sensitive to what THEY are OK with...have a conversation.
I personally wouldn't think twice about sharing my tub with a snake, that's where my dogs are bathed too. But you may have to compromise for "peace".