I agree with Steve with the Bentonite
or activated charcoal (I really find charcoal effective). You could also take a formulation to support the liver.
I was experiencing intense stiffness and pain in my shoulder and neck and just around the time I started my first liver flush, it went away, almost before, but I had prefaced my first Liver Flush
by taking Renew Life Liver Cleanse for ten days prior (it's a 30 day cleanse and all you do is take capsules in the morning and evening), so I kind of think that had something to do with the alleviation of the stiffness and soreness along with subsequent flushing.
I'm currently taking Dr. Christopher's Liver and Gallbladder formula, not sure if it would do exactly the same thing but I'm taking it to support my liver.