100% pure. You let it sit for five minutes so it gets in the grain and then wipe it out. It's good enough for my hard wood floors, should be OK for a fretboard.
Robert, Just curious, have you considered the foam trick to make your pickups more parallel to the strings?
For humbuckers, there's two ways to go. http://www.everythingsg.com/threads/fix-your-tilted-pickups.23022/
DrBGood posted an illustration. Many folks will put stiff foam in the pickup cavity underneath the rear edge of the pickup. Once the pickguard is screwed back down the foam essentially forces the pickup to be parallel with the strings. In SGs that have the small pickguard, the pickup rings are beveled so this is not as necessary. The pickup ring, itself, helps angle the pickup to keep it parallel. However, even with pickup rings it can still occasionally be necessary to use the foam. The idea is that with the angle of the strings, one coil of the humbucker will be closer than the other. By forcing the pickup to be parallel, both coils will be about the same distance from the strings. Consequently, it can provide a little fuller sound.
And it look much better. I'm still amazed it's not a stock thing on guitars to have tilted pickups. It is such a simple thing that make a guitar look like it was designed with some care.
In a way it is a stock thing to make sure they're tilted...IF you have the small pick guard. As I mentioned, the pickup rings are angled (i.e., slightly wedge-shaped) on small pick guard SGs, as well as other Gibsons that use the rings. My Les Paul has angled rings, too. So, Gibson has made the attempt to tilt the pickups parallel to the strings. But, even with the angled rings, sometimes the pickup will still need more assistance. I had to use the foam trick on my '74, even though it has angled rings.
BTW, since we were also talking the pickup angle, I took a shot of my SG Original 2. This has the beveled pickup rings. The pickups are parallel to the strings. I haven't needed to do the foam trick to this one, though I did need to with my '74.
