Probably not as it's a type of clay. But of course many just think of the
glazed finish it commonly has in practice. And that glaze is very similar
to vitreous enamel, both being basically glass.



Getting back to the OP, I generally clean the grill by getting it bleedin
hot over the charcoal and burning off any food residue. Any bugs that
survive deserve to live.

Whatever the material used by Outback for their grills, they describe the
grill as porcelain coated as do other manufactures. They also described it
as heatproof which is obviously relative to typical BBQ temperatures. There
is little doubt that the damage to the grill is caused by exessive heat from
the charcoal. The damage is a bubbling of the coating which changes from a
smooth surface to something like that of cast iron. I use a chimney starter
to light the charcoal and it gets very hot, presumably hotter than the
temperature required to melt the porelain /enamel coating.