the mercury that escapes the fillings comes off as a vapor, not as a liguid or such. this vapor is then inhaled into the lungs and is drawn directly into the bloodstream where it travels throughout the body and is deposited in all tissues. oil pulling will actually give you a 15 minute respite from ingesting the mercury. hot food and drink and chewing friction(heat) both significantly increase the amount of mercury released.
when the dentist takes them out, the epa makes them store them in a glass container in a glycerine bath. they can get fined if they release these into the environment and fail to store them properly.
the thing to do until one gets them all out is learn how to breath in through the nose and out through the mouth. this decreases absorption as much as anything else you can do short of removal.