I have come to this conclusion as well. Heavy metals work right along with the candida, and candida has shown to amplify mercury by 100x (converts it to methyl mercury I believe). And I take diatomaceous earth to keep parasite free.
So diet alone won't completely clear you, chelation alone won't either, and taking anti-fungals and probiotics alone won't clear you. I feel I am in the "clear" with the above mentioned except for chelation, but I think my health would benefit from getting rid of these Amalgams and heavy metals. It is next on my list.
That being said, I do eat healthy on a daily basis with lots of sprouts, greens, meats, quinoa, etc., but it doesn't do any harm for me to have an occasional glass of wine, coffee, crackers, pizza, and the like. I have lost my taste for sugar.
So, it may be possible for the candida to come back if I stopped drinking kefir and ate crap all the time. I am unsure if EVERY last colony has been knocked out, as candida is tricky and will go into hiding when it's lost the battle - and just waits for an opportunity.