pollen being microscopic

[fed]

Yo, Ron; An update on the soil-grown, over-fed, flowering plant. It turned out to be a beauty! Unfortunately, when I severely topped the plant, it created hermaphrodites, which, in turn, pollinated the entire plant. Harvested same before it could ruin the crop. Now, with pollen being microscopic, what would you use, or how would you prep the grow room for the next batch - getting rid of the pollen so it doesn't pollinate my next girls? Does pollen die after a while?