Originally Posted by zap2504
Also (from previous posts):
"With nothing to lose, I immersed them in lacquer thinner and checked them twice a day. The things swell up and you would swear that they are ruined, but they shrink back to normal in a few days. Some guys also use wintergreen available at drug stores and make some sort of brew mixing it with the solvent. I just use the lacquer thinner until the boots soften enough and then soak the boots in the wintergreen for a day. As they start to shrink, the wintergreen sucks in to the rubber. The wintergreen at a cheaper price is also known as Thor Tire Prep #12 and available at kart shops to soften racing tires."
The wintergreen oil also is great for use on badly rusted fasteners. We used it on flange joint bolts on steam lines.