I've tried Easy Off. It will remove the oil in the stock, it keeps weeping oil for a while, and you have to remove it. I can't tell any damage to the stock, but then the stock I used it on was a P 14 Enfield, and it had LOTS of grease in it. It looked fine for a miltary rifle.

How it would work on a fine gun, I don't know. I think you'd have to do a lot of work on regaining the grain of the stock and possibly filling the pores. But as for removing grease and oil, it does a fine job.