Good lord.

Glass tile does not need sealing. It's not porous!

And honestly, neither does grout on a kitchen backsplash wall. Most grouts are modified and are plenty "sturdy enough" to deal with surviving unsealed on a wall, even a kitchen backsplash wall.

If I DID want to seal your grout, I would have applied the sealer just to the grout with a brush. Had any sealer gotten on the glass tile by mistake, I would have wiped it off immediately and not allowed it to dry on the surface of the glass. No how. No way.

Regardless, the products he used are typically used as sealers on porous tiles; natural stone, saltillo, brick, etc. And grout too if needed. But not on glass tile.

I highly recommend YOU call Custom's tech department. Tell them your story, and see if they can offer any advice. They may be able to tell you what stripper could possibly be used to remove the sealer, but in no way will they be able to guaranty that it won't affect the frost finish on the glass tile. Or that it will return your tile to it's "pre-sealed look". Nor should they, since for the most part, the product was improperly used.

800.282.8786

Best of luck...and my condolences.

If the tile face is smooth enough, a lot of single edge razor blades are in someones future.

You could try Barkeeper's Friend and a nylon scrubby first on a small area, otherwise I'd invest in a larger jug of the following.

Here is a link that might be useful: Aquamix sealer and adhesive remover

"You could try Barkeeper's Friend and a nylon scrubby first on a small area"

Be very careful.

Glass tiles are often not all that hard and easily scratched (by powder scrubbers or metal razor blades).

A plastic scrapper is safer, but may not be hard enough to do the job.

If you use chemicals you have to be sire they do not carry anything into the grout joints and cause color changes.