Terry, Tod, 15 years of using Thompson's Water Sealer on brown cork with no paint sluffing problems has made a believer out of me as to how well oil based paints (which is all I use) sticks to cork treated by Thompson's. Mind you, you have to give it 48 hours to fully dry, but once its dry, the paint sticks.
I have a couple of cork decoys I painted back in '95 that are still holding their original paint. I also have a couple I carved and painted before I started using Thompson's that I've had to retire 'cause in 4 or 5 hours they soak up so much water they appear to be sinking.
Back when I used a lot of basswood, I sealed them with Thompson's also. I'd go so far as to say the basswood I had, wicked water worse than the cork I used back then. None of those decoys ever shed their paint.
Before you go telling somebody whose been doing something a long time that it won't work, you ought to try it.
John Bourbon