Weeeeeellllllllll... S10's are sweaty bastards certainly, but let's have it right, the way that the air circulates inside them with each breath, as it is designed to, stops the lenses from fogging much / at all. Who knows if that will still work properly if you mess with it?
I haven't got around to it yet, but I definitely intend to take the innards out of a filter for mine sometime. Breathing through a proper filter takes some practice when you're running about - deep and steady gets you more oxygen than trying to gasp.
I had a look for my receipt for ballistic replacement lenses, so i could pass on the seller to you, but unfortunately it's another victim of early onset dementia, otherwise known as i couldn't fcuking remember where i've left my arse if i didn't have to wipe it periodically...