I'm familiar with that trick, I also know it will not stand the test of time on a car that gets a lot of seat time with multi hour road trips. I travel 7+ hours one way for work each week, the numb butt stops have gotten more frequent recently. If I'm going to pull the seats and seat bottom cushions, I am replacing the foam vs. steaming it. Pulling them to steam it again every 25k miles isnt worth it for me when new seat foam should be comfortable for another 100k.
Bump to the top for replacement seat foam on multi contour seats w/ Heat and A/C