kashering

Question

I looked at your section on kashering, but I still have two questions. What can be done with a so-called 'cook top' which is a glass surface(possibly covered in enamel) which you directly place pots on when cooking, and tends to have a lot of food splatter on it. Second, what should be done about a sink which is porcelain- do you have to worry about splattering, leaving dishes in it, etc, etc.