I brought one of these masks and have never been able to use it due to constant fogging. I've tried everything conceivable to fix it but no luck.
Be interested to hear how get on.
With my last two masks I had fogging issues. I tried the toothpaste method and lighter trick but it often still fogged.
I find that if I take the mask off at the surface after diving for a while, then I get the fogging.
I starting using anti fog spray which works well. Spit works also but I often have a dry mouth.
My anti fog spray ran out last week, I refilled it with Johnson's Baby Shampoo + little bit of water and it works just as well. I keep the spray on a flexible leash on my float so it's easy to get to. Over a 5 hour session the other day I sprayed my mask 3 times. I won't go in the water without it.