Comic book pressing removes bends, creases and other imperfections. It improves the overall appearance and value of the book. It will not remove color breaks and does not fix all damage.
Foil cover books like Venom Lethal Protector can be pressed with limited expectatons
Embossed Covered books cannot be pressed as they become "enflattened".
Dry/wet Cleaning is used to remove most of the surface dirt on the front and back cover. It can remove pencil and some ink (but not all). It is not suitable for all books and does not remove all markings. It does not typically remove stains, soiling, ink or water damage.
Spine Roll is a fix for books with a mis-aligned spine. It is only for books that are in good condition, as it can cause damage to brittle books. (Spine Roll is not when the book has a curl to it, that is fixed by normal pressing)