I applied it with a paint brush while they were in there. All the other times I open the lobster tub the adults are climbing out along the rim and jumping down. This time they stayed put (maybe because I fed them a whole banana a day before) and they stayed down while I painted the top 2 inches with the fluon.
Again, I think it's overpriced, and probably not much different from teflon paint. But I've read no negative reviews on fluon and a couple on teflon paint not working for some roaches so I erred on the side of caution and bought this stuff. The best of all is I finally put some on the feeder cups for my chameleon cages and the damn roaches finally stay in there! It dries white and patchy, and looks just like whiteout, but that's how you know you put enough on there.