I slabbed up two white oak logs this past weekend. A total of 12 slabs, 10 feet long and average of 24" wide. I used 2 chains and at the end of the day both had a lot of pitch/resin on them. It was like a cured coating of polyurethane. I tried kerosene, acetone, methyl alcohol, WD-40, and Goo-Gone. None of them would cut through that film. I was taking a razor blade to get it to come loose.
I then remembered that I had some Totally Awesome Cleaner that comes from Family Dollar and Dollar General. I mixed some with water at about 20% ratio of cleaner. I soaked the chains for around 30 minutes and I could brush them lightly with a brass brush and they came completely clean. This stuff is $3.25 for a half gallon in my neck of the woods. It is a great degreaser also.