To the best of my knowledge, it's the enzyme within the d /m's digestive system that actually causes the problem.
So......
Kill the dustmites, which I know Promite will do, possibly others, also, but I have no first hand knowledge of this,
Thoroughly clean with your personal choice of product.
Apply an acaricide type product which is known to remain active for 6-12 months
Advise the client about the importance of air flow throughout the house..........
Advise client about the importance of proper and regular vacuuming, ideally with water filtration, which is far superior to any dry fotm of filtration and is not expensive. .....An opportunity to sell an ethical and genuine, health improvement product.
Advise client about regular professional cleaning to maintain their healthier environment.
OK let the arrows fly...........but, that is the reality unless you know better.
this is the approach I take and probably quite a few others, except for water filtration, which some of you might have no knowledge of and out of respect for the Host I won't suggest any particular supplier, but there is a machine made for a British supplier, to their spec' which you can buy for less than two hundred pounds
Bye
r m
Apply a