May I go bullsh1&@ing? After many trials and attempts I found out that spitting on the mask is the best way to defog it. 5 or 10 minutes before the dive one spit on the internal left side of the mask, then another one on the internal right side. You spread the spit over the glass with the finger and it’s done. You can’t forget this defogger at home and the result is guaranteed. No environmental pollution, no chemicals in contact with your eyes