I spent part of last night paging through your thread. Nice job!
My airbrush is old as anything, and I've never been able to get it to be consistant. (I got it for Christmas when I was around 13.) I have a compressor that runs non-stop (no container to build up pressure), and it rattles off anything I put it on. The idea of using a spray bottle sounded extremely do-able, without having to deal with my airbrush issues. I've got acryllic paints already...just need a spray bottle I don't mind trashing on paint filled water.
I do want to look into the Dirty Down sprays. I expect to be washing the suit often enough (I live in west-central Florida), so I want something that's not going to wash itself out.