Product review (1 stars): The Granite Grabbers That Don't Really Grab!
After getting two sets of these (one for my parents and one for myself) they failed in both situations.  The brackets are fantastic, but the durability of the adhesive seems to fail rather quickly.  I cleaned the granite as requested and had no luck in either application.  It seems as though the steam, IMO, from the drying cycle may aid in making the adhesive unreliable.  The seller obviously knows about the issue, but continues to sell them without any type of solution other than using epoxy.  For some it seems to work, but for this guy Ive found myself very unhappy with this product.