We had maple kitchen cabinets professionally installed 18 years ago and have kept them clean with wise use of gentle wood cleaners. However, the area above the stove, which has two wood panels covering the exhaust fan, is covered with an invisible sticky grease residue. Nothing we have tried has worked to clean away the stickiness. Of course we have not used any abrasives or strong chemicals so as not to mar the finish. Any suggestions, short of stripping and refinishing (which would stick out as the other cubboards have yellowed slightly over the years)? Thanks for any help!