I started to place another order and went right up to the payment page, so yes his "business" is continuing.
I think I'm going to try to make my own. According to Dick Dokas, by using the right abrasives, you can produce a gg at least one stop brighter than the norm. Doesn't seem that difficult... maybe I should go into the business.
Dokas link at: http://www.dokasphotos.com/techniques/ground_glass/