^^^ I scrape the ugly discolored stuff off the surface and I stop when I get down to the good viable stuff, underneath, and then I put a layer of new caulk on top.
As far as a solvent that cuts the caulks fairly well w/o dissolving the everything else... I've had good luck with naptha or lo-vol mineral spirits, depending on the type of caulk. Craig
2012 Dodge 3500 DRW CCLB 4wd, custom hauler bed.
2008 Sunnybrook Titan 30 RKFS Morryde and Disc brakes
WILL ROGERS NEVER MET JOE BIDEN!