I'm in an apartment. I *could* wash my bikes indoors, but I don't.
I trundle out the bike to the back yard or parking lot, toting a bucket of warm water with Dawn, a spray bottle of generic "green" degreaser, some junk brushes and sponges, and do it quick and semi-dirty. I'm not that picky, just knock of the mud and worst road grime.
Switching to cleaner chain lubes cut down on some grime. I use either hot wax (a hassle to set up but easy once the process is underway) or Rock 'n' Roll Absolute Dry or Gold, both very light lubes that are mostly naphtha carrier with PTFE, and with the Gold, a bit of oil. I dribble a few droplets using a needle dropper once a week, kinda randomly. That's cut way back on the mess from oily lubes that collect grime and splatter the bike.