It can but isn't as harsh as Brake Fluid and it will help loosen things up. I'd try penetrating oil before using Brake Fluid. Brake Fluid would cut right through the paint but it would run all over and make a mess of everything that has been painted. I'd save that as the last resort (if it is paint that when sprayed on penetrated and gummed up the joints that is causing the problem). The OP isn't sure if it is paint in the joints that is causing the problem, it's just quite a coincidence that it was working fine until everything got sprayed with paint.