If you have to wear 2 masks now to keep your toxic wet breath spew from exiting into the air then how big a mask do you need for virus expelled by the rear in a bad gas attack? An exit of air from that region expels at much higher volume and speed of say a cough evidenced by the lingering odor of the expelled air. Plus if you’re wearing 2 masks and can smell a fart from a covid carrier then you’re dead meat, it’s too late for you.