Of course it would
Unless, you have a urethane finish?
There's little that would effect plastic!
I have several stocks that are finished in OTHER THAN urethane for easthetic reasons, and have used Olde English on for years. However and for about the last decade have been using a mixture of Linseed oil,Beeswax and turpentine.
Over time this builds up into a water-resistant finish that enhances the looks of a fine stock, and even mil-surp rifles.
The formula I use is one part each,melt the wax(careful here) add turps and
linseed oil,pour up into jars or tins and let cool. It will reach the consistancy of
shoe polish,which will liquify as you rub it in, hope this helps
robert
p.s. avoid boiled linseed oil, as it is not the same as our grandfathers used and contains lead.