I think they make scuba mask spray that stops fogging.
The reason fog occurs is that there are two different temperatures inside the helm and outside the helm. Same as any fogging windows etc.
More ventilation helps. I went to a costume party last year, and it was HOT. It fogged so I took a piece of curved paper and put it inside. so it forced the air out the bottom.
and didnt allow it up into the eye area.
I got some motorbike antifog spray for mine, and apart from dramatic temperature changes (like going from really cold outside, to a really warm inside) it stopped the fogging really well and allowed my to troop all day with minimum visor wipes
I used every method to keep fogging down, but honestly there
will always be "some" fogging build up no matter what you use
pending how hard you breath.
I'll still use the options that was mention here on the thread.
The fans do help a bit though. Good Luck!
i went to a ski doo store today and asked them for some anti fogging solution, they told me to use SUNLIGHT DISH DETERGENT i did and it worked awesome!!!