Gray, I'm another apartment dweller, and I give my bike a wash and blowdry whenever I've ridden in the rain. I take off my front wheel and put it in my bathtub. I spray clingon degreaser and let it sit for a few minutes. Then I use my handheld shower massage to gently rinse away the filthy road grime. I also use a sponge and a little soap to get at the frame when it needs it. Afterwards I towel dry, turn the bike over and take off the rear wheel and clean the cassette etc making sure to dry all the parts thoroughly using my hair dryer. Seriously. Its clean and shiny and ready for grease

This may seem crazy but it works. Oh, and it give you a great excuse to clean the tub! Might recommend a cheap rubber bathmat in the bottom of the tub so the front fork doesn't scratch anything. It also catches the worst of the gunk.