4

If you're conditioning your mask for the first time after buying it, you'll want to let it dry, and then repeat the process about 5 times.

Use clean, fresh water to clean the toothpaste off the mask. It may take a bit of elbow grease to get it all off, but it should eventually come off. Once it's off, dry off the lens. Try breathing on the mask to see if it fogs. If it does, try doing the whole thing over again.