And the more apropriate question is what is your intended end result?
You could use peel away, which would be somewhat less of a project, but can darken some woods. Your other choice is a Methylene Chloride remover, very caustic and also carcinogenic. Methylene will melt most plastics and it has a strong odor that can be harmful as well, you need good, contant ventilation to use this stuff
Again, the question is how bad do you really want to do this?