you have to associate the human with their death then they don"t want that human any more
Interesting theory. Bedbugs are clever in their own way but I don't think they recognise individual humans. The ones we had did not start preferring my husband when I was the one dismantling the bed and raining death upon them week after week after fucking week.
DE and Cimexa are both dusts which work mechanically rather than chemically - i.e. they physically injure the bugs and dry them out rather than poisoning them. This means they are less likely to develop resistance although there is now some evidence that they are starting to evolve thicker exoskeletons in response to exposure to these dusts*
Nevertheless, DE takes up to 14 days to kill adult bugs whereas cimexa takes up to 4 days.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5198222/
Juvenile bedbugs moult every 5-8 days. So cimexa will kill them before they moult whereas DE will not.
So with DE they moult, they get a new exoskeleton, the clock starts again. Only when they reach adulthood and stop moulting will their exoskeleton be exposed to the DE for the required 14 days.
An adult female will mate within 1-2 days of her final moult and 1-2 days after that will start laying up to 5 eggs per day. So she can lay about 60 eggs before the DE finally kills her. And each of those 60 babies will survive til adulthood + 14 days ...
https://www.vdacs.virginia.gov/pdf/bb-biology1.pdf
(contains pictures of bedbugs)
So that's why I say don't bother with diatomaceous earth. Use the stuff that kills them the quickest, before they get a chance to breed, before they get a chance to evolve further resistance.
To be clear, this is not a brand ad for cimexa, which is often difficult to get hold of in the UK. I learnt recently on another thread that there's a similar product called chinchex which is licenced for the UK. There may also be other brands available now, I don't know. Whatever it's called, the product you need is silicon dioxide in a very fine powder form suitable for pest control.
*It's quite likely we will also see some evolved resistance to heat treatments in the near future - these fuckers will be with us to the end.