I haven't got back into it again yet but I was doing it pre-pregnancy. I, too, became "addicted" to the feeling of a nice clean mouth. I was OPing at night with safflower oil as I'd heard it helps with sleep and in the morning with olive oil.
While I was OPing, my gums stopped receding and bleeding, my teeth got a little whiter, and I noticed that I stopped having tonsiliths (gross, if you don't know what they are, don't look them up). And that was only in a few (6-8?) weeks.
I have amalgam fillings as well and didn't notice any detox symptoms. I worked up to 15 minutes twice per day (as explained above). I was also nursing.
hmmm. maybe extra vit c would help