I don't know about in the US but here we can get a finish cleaner. It's meant to clean the sweat and associated grime off oiled finishes. I have soem that came in a stock finish kit which has stuff to maintain as well as completly re-finish a stock. I used the cleaned on an old rifle ans the difference in the finish afterwards was quite outstanding as was the amount of crud that came off on the cloth used
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I then rubbed on a tiny amount of stock conditioning oil and it looks miles better.
Which reminds me I need to do teh same to my P-H 1100 De Luxe as it seems to have some sort of wax on it that a previous owner had used.