Hello, I own a Desert Tortoise by the name of Michelangelo. I've had Mickey since I was a young boy he was a hatching. Today he's about 12 years old. Recently he had wandered to under my grill in my back yard. He's never done this before, I actually had to fish him out myself. Once I had grabbed him I noticed he was covered in oils.. I know the oils can't be good but I can't seem to remove them.. they have been lingering on his shell for the past three months; set through hibernation. I have been able to remove some of the oils but it still feels the stuff is nearly unremoveable. Any help or suggestions will be highly appreciated