Pollen from a sativa male stays viable on tent walls, fans, and clothing for weeks, and a careless breeding run can seed the next three crops. Wiping every surface with water and a little soap, running the extraction on full for a few days, and washing anything that was in the room are the minimum before bringing females back in. The breeding safety notes on https://hazesativaseeds.com go further and recommend a separate room with its own extraction for any male work. Misting the male with water before moving it stops most of the drift in the first place.
