Go for it. You've clearly thought it through. I'm not opposed. Not terribly excited, but not opposed. I'd submit any really interesting or historically significant ones I came across but I don't think I'd follow the utilitarian spirit of submitting lots of them.
You've got me wondering whether to propose "converted public toilets" ... nah ... Seeing that I can think of a grand total of two I think it would be a leeetle bit short on prevalence.