Borax. Spread it into all the corners, esp. around doors, and if you have carpet, sweep it into the carpet. The crystals will cut into the exoskeletons and kill them.
You could also try Demon WP which is an incredibly potent insecticide, but I wouldn’t recommend spraying your carpets if you have toddlers or other pets.
Do you mean diatomaceous earth?
we had a cat initiated flea attack. we did get rid of the cat, but then also got rid of the fleas in one sot.
we used plain old flea bombs in the infected room, multiple i recall, but you have to ec=vacuate for a while as they work.
then, we brought in an exterminator who hosed down our whole lot with a liquid containing nematodes i believe. that worked, never had a re infestation.
not exactly sure what a nematode is or how it works, but it worked.