I have stained kitchen cabinets that I need to clean. I am not sure of the wood, it is a softer wood...pine or birch? My problem is on top of the cabinets. Years of grime have built up on top (they are not enclosed to the ceiling). I have tried Murphy's Oil Soap to no avail. I scraped a good amount of the grime off, but it still needs to be cleaned. I am not sure if the wood was sealed, so I hesitate to use TSP. Any suggestions?