I only needed two treatments to rid my place off a out-of-control flea problem (everything else failed, even bombs) I also used “The Program” (lufenuron). I gave them the Program first, then 2 weeks later used the capstar, two weeks later another Program and then the final capstar (which wasn’t really needed at that point)

To borax treat carpet, buy a thing of borax (in the laundry aisle at grocery stores) and mix it with about 1-2parts salt to 3-4 parts borax and then lightly spread evenly over carpet, then work it into carpet (I used a push broom) let it sit for 1-2 hours and then vacuum (use a new vacuum bag, don’t use a bagless, it will destroy the filter) Remember to wear a breathing mask will during all stages as the dust is dangerous to breath in (for humans and all animals) but once it’s settled it’s virtually harmless. Vacuum every day 1-2 times a day only reapply borax mixture about once a week. This treatment also help rid of ants, spiders and cockroaches that walk across the carpet.

Always remember to consult a professional veterinary doctor before taking any of my advise as I am not a qualified professional, just an experienced cat lover.