Cordless-Drills.net is selling what looks to be a really cheaply made air caulking gun for only $8. If you’re doing a caulking project that requires multiple tubes, you’ll soon discover that the muscles in the hand aren’t meant to be squeezed repeatedly for hours. For these jobs, an air-powered caulking gun will save you a lot of time and pain.
Will this one hold up? Hard to say — but it’s cheap enough that if it just works for one big job, you’re going to be happy.