M.,
I am chuckling a bit too... I know this sucks for you... laundry, baths daily, the stink, and having to clean up - ugh!
If it's any consolation... my daughter did this too, BUT, she would play with her poop!!! Her wall was painted with a textured paint (stucco) and so she would use her poop as an art medium and paint the walls with it.. .she liked how the bumps on the wall came through and the poop settled in the little nooks and crannies - i washed that wall at least once a week with a toothbrush to get all the poop out of the crevices. It was moments like that I knew why parents sometimes spanked their kids... I'm an hour late for work, my boss is pissed, and I am scrubbing poop off the walls.
I would put her into a pull up type diaper at night (jewel has a store brand that aren't nearly as costly as the pull ups brand are) - those things are tough to get off... we rip the sides open to get them off. Also, keep a onesie on her like the other mom suggested. If you get some brand new (some of our hand me down onesies snaps have worn out a bit and snap open easily) they should be really hard to unsnap.
Good luck :)