This is just an idea... Bentonite clay is so good at drawing out toxins from skin, it's really powerful, I'm wondering... What if you filled your mouth with hydrated Bentonite clay and sat with it in your mouth, being very careful not to swallow and making sure it had contact with your gums and tong, for 20 min? I bet it would draw out all the toxins in your mouth, albeit temporarily, should give you some relief.
P&B shakes will draw out heavy metals from the bowels.
Wheatgrass, Spirulina and Chlorella are used in detoxing heavy metals.