I did this a while ago with some clear glass bottles. The paint eventually started to peel away, which made a mess, and some of it got into the bottles, which of course is bad. I don't recommend this. IMHO, it'd be better to wrap bottles in paper or aluminum foil if you're concerned about making clear bottles more light-resistant.
I assume you're referring to squeezing plastic bottles to expel unwanted air. That only works so far, and only with some bottles, but I suppose it works well enough up to a point. Note that photo stores sell accordion bottles that are designed with this sort of thing in mind. I have yet to see any real person actually recommend them, though. They're difficult to clean and the ones I've seen are made of HDPE, which isn't a desirable type of plastic for developers. I bought a few of these when I first started doing my own developing, but I ended up putting them out with my recyclables.