I'm so glad I gave up on them and sent mine back. Nice example of false economy.
Now that I got that out of my system...considering how minimal the "PU coating" is on these, I would try the silicone/mineral spirits solution on a small test area. If it soaks in vs. laying on the surface, it should do the job.
Edit...try applying it on the "outside" of the tarp since PU tarps normally orient the coating to the "inside".
Last edited by gmcttr; 10-20-2012 at 10:53..