I have seen posts saying that persons have baked in garden clay pots (vs.
clay pots made for cooking).

My 2 cents worth:
I wouldn't want to baking in anything made for the garden and not made
specifically FOR cooking. I know people do this, but I think this calls for
thought on one's part before doing it.

I will say that I have never heard that it IS dangerous, but I have never
researched ("googled" it. It seems like common sense to me not to cook in
garden utensils where there are not manufactured under Safety Cooking
Regulations. I don't know what these regulations are called, but I do know
that I have purchased plastic containers that have had a Code on them for
safety and I have seen warnings about lead being in dishes made in certain
countries for their ceramic cookware, as well as lead in crystal.

Dee