Half and half, the herxeimer reaction happens because the dieoff occurs faster then the liver can clear..
And candida can thrive and inhibit the detox process in quite a terrible way! I'd be wary of allowing candida to feed off of your efforts and comprimising the efficacy of the chelation.
I chose sweating as opposed to chelation myself due to wanting to avoid issues with pushing Mercury and the like towards the brain and the kidneys. The efficacy of sauna treatment to chelation treatment is considerable, and I do use the active ingredient Lignisul MSM to kick out the mercury bit by bit. see my other post on this thread for details. :)