2x2 tile glue problem.. solved
 

Okay my dad has a machine shop and has a heat treat furnace and he put the tiles in it at 1100 degrees for a while and it burnt that gook off. And then I washed them in soap and water to take off the ashes... So if you have a way to get them that hot it will work.. (It does smell the place up however, so be wary of your household oven in a not ventilated space)
Tammi