Have you got any sort of closet or area that you could keep one bucket?
If so check out the gamma lids. They fit most 5 gal buckets. If you have room to hide one bucket the lid screws on pretty tight and would hide the contents pretty well for you. I know barracks can be tough, I've seen the living "spaces" of a few guys I used to know. I bet you could hide a single bucket inside your car if you had to.
Seriously compact wash kit:
One bucket with a grit guard and some ONR (optimum no rinse), one sponge, and a couple drying towels would allow you to do some maintenance washes. I fill mine in the kitchen sink here at my apartment. The complex gives me some guff about washing but they really can't say much since im out there using less than 5gal of water. Pick up a quick detail spray or a spray wax and a couple MF towels. Wash and shine from one bucket. Hide it in the back seat.
Gamma Lids: You can get them lots of places online. Maybe even pick up a color matched bucket too! hahahah
http://www.usplastic.com/catalog/item.aspx?itemid=24282
ONR: Seriously awesome. It removed road grime better than the touchless wash down the street
http://www.detailedimage.com/Optimum-OPT-M36/No-Rinse-Wash-Shine-2010-Formula-P444/32oz-S1/
Washing with ONR: I like to use a sponge, get it pretty wet and as I move it over the paint, squeeze the solution out of the sponge to glide the dirt off. I only use one bucket instead of two just cause im trying to be as discrete as possible. Couple articles to check out. I like the first one better but the second gives more of an idea how to use the stuff. I have almost no water left in the bucket by the time I am done. I try to get it all on the car. Work from top to bottom one side then the other. I dry each section as I finish it.
http://www.detailedimage.com/Ask-a-Pro/wash-and-wax-in-60-minutes-featuring-optimum-no-rinse/
http://www.detailedimage.com/Ask-a-Pro/winter-washing-with-optimum-no-rinse-onr/