Cleaning Cab Tolex

[ZakkWylde91]

I bought an 80's Marshall Jcm800 cab loaded with G12-65 and the previous owner treat the cab with a sort of tire cleaner stuff, and now it's greasy as hell. Not only that, when I press my finger on the cab and rub my finger become black. How can I clean it, cause I tried hot water, Windex and it's still sweating black hehehe

Thanks for your help!