If you decide to do a deep cleaning and refinish of the wood here is how I do it. Takes maybe 10 -15 minutes for a completetly clean bare stock . Its a really simple ,easy and alot less harsh than other methods
I first take Purple Power degreaser full strength and put it in a spray bottle.

I then spray down the stock with full strength degreaser, immediataly you will see years of grease. oil and dirt start to roll off

I then take a soft nylon bristle brush and go over the stock.
Rinse very well with hot water while rubbing with brush .
I will usually do procedure one more time except the last time wipe dry with cotton towel.
If stock is very oil soaked it may take another cleaning .
I then let the stock set to dry out of direct heat source.
If it drys slowly you have a less chance of wood warping.

This is what the wood looks like after drying


I let the stock dry for a day or two before refinishing