I have gased with c02 at 4000ppm for up to 4 hrs at a time with little damage. And I did this daily for 1wk had some effect on the tssm but didnt do a total knock down, the eggs didnt die they can hatch up to 30 days after you think you got rid of them. I.P.M. means integrated pest management. you are likely aware of gestation period of tssm. and that the eggs will hatch after you smother the parents, so first knock down population then hit em again after eggs hatch 48-72hrs and then once more it takes a week to do a total knock down of tssm. they are born pregnant and become resistant very fast. I use predators oils soaps and gasses, I was very sad when I had to do a total knock down last spring, it killed my old and established predator population as well. I should have collected some to reintroduce.