“Years ago I suggested on this web site, orange hand cleaner for removal of oil/tar. Spike emailed me asking that I keep an eye on the cleaned area for signs of “reactions”. I still have the OK Scrambler. The area cleaned looks the same as the rest of the kayak. I do store the kayak
indoors and use “303” protectant about once per month. Perhaps the extra care has been helpful.” 

Thanks to Bill Hartman, Oxnard California.