Hi Skies, sorry to hear this. I could not recover from an infection I developed last year because I kept eating bits of sugar here and there and all it did was keep the infection going or flare it back up again.

Everytime I got really strict, it would seem to start subsiding, but one cheat and it woudl worsen again. All that because I wouldn't stick to the diet and I wound up receiving antibiotics and sure the infection finally went, but I've been left with a much worse case of yeast problems ever since.

I'd imagine that some of this could well have its basis in mercury exposure, but that's a tough one to do much about when it's someone else's kid. I cannot imagine the mother would have him on chelation!

I think garlic maybe a great one to use. Plus sosick has received help with her mercury from garlic and cilantro. However, people respond differently to those products and normally it's not advised to use an agent that chelates the brain until body levels are reduced first. However even Andy does state that some who cannot tolerate the other agents, "can" try cilantro. But again, people seem to respond differently and these are natural products, one does not need to go overboard with them either.

Garlic, lemon juice, cilantro (?), vitamin C, and to make sure he gets plenty of protein and iron in meat and eggs and of course antioxidants in fruits/vegetables (oranges, carrots, broccoli etc) and good animal fats like butter and cod liver oil as sosick mentioned for vitamin A and D and omega 3. And avoiding junkfood as much as possible. Substituting it with some natural treats from a healthfood shop is what I would do! - carob instead of sweetened chocolate. Or the natural chocolate treats people have already mentioned on here.

Natural yoghurt poured on top of fruit for pudding. Things like this. Oats porridge etc.

There is a cilantro pesto for mercury toxicity, that apparenty tastes delicious that includes garlic, lemon juice and I think nuts as well as the cilantro. I'm sure this could be eaten straight or put into potatoes or something.
http://www.awakening-healing.com/A-HNewsLetters/2003/Heavy_Metal_Pesto.htm

Wish I could be of more help!! I think the child needs to be removed from all sugar/junkfood and substituted with every healthy food possible, so his immunity can get the help it desperately needs and infection can be fought better. Plus if he's got mercury/candida, that too will should be helped with all this. It may not be perfect, but it's something.