Mine only tend to get cleaned once a year when I swap the downstairs-in-the-lobby daily ride - the winter hack is down there now. I've been meaning to go down with a bucket of water to take it outside to wash off the salty gunk.
Otherwise, I sometimes clean up here - lots of newspaper down, or take stuff into the kitchenette which has a mopable floor. Any upstairs cleaning tends to be muk-off type polishing on a small scale, than anything with buckets of water.
Luckily, the landlord is not too fussy about the odd tyre mark on the walls from carrying bikes up and down - it's the carrying that can put me off going out on one of the upstairs bikes. Carrying it down is worse than up, I find, because the back end is heavier,so hangs lower, and knocks against the stair behind me. I've tried carrying it arse-end-first, but then the handlebars get me in the back of the neck.