Safe To Ingest Black Walnut Hull

I have been taking Black-Walnut hull as a homemade paste (ground it up in a blender and mixed it with water) and I leave it on my teeth when I go to sleep to regrow my cavities. I am curious if it's ok to accidentally ingest a little bit, since all of the information I read is only read about it being used for external wounds.

Also this has me wondering if it can be used for treating people with stomache ulcers? This is a problem that my brother has.

Also how/when should I get my old Amalgam fillings removed? Would it interfere with their remineralization? I have one filling that is getting worn away.