I know hot water will kill dust mites, but it wears out your clothes. Is there another way to kill them? Won’t they drown eventually if you leave the clothes soaking?
Yes, there are laundry additives that you can buy that kill dustmites. I buy mine from www.nationalallergy.com
It is not just a question of killing the dustmites, because they still contain the allergen when they are dead. Also, their feces contain the allergen. I believe the additives work by neutralizing the allergenic protein. A lot of what causes the allergy is the presence of carcasses and parts. There area also sprays for carpeting and upholstery.
When I was first diagnosed I used these a lot. After treating a room or my car, etc. the air just plain felt better when I inhaled it, it was kind of amazing.
Which laundry additive? What carpet cleaner? There are too many choices with too many price differentials on the site! What works for you, Hariret the Spry?
Why wouldn’t plain ol’ laundry detergent do that? One of the properties of soap is that it acts as a surfactant , decreasing surface tension .
I use laundry detergent and on sheets/linens I use hot water and I’m still having the worst allergy symptoms I’ve ever had this year!!
Huh.
I wonder if dust mites are just too small to be affected by regular detergent?
Well, someone who really knows is likely to come along. Or, someone with a Google fix to satiate! 
Have you tried The Allergy Store ?
I use the De-Mite laundry additive and the Dustmite and Flea carpet spray. The spray is kind of a pain, since you have to mix it from a powder. I have also used the Allersafe Dustroy stuff. It worked well, too, but seemed kind of expensive for spraying large areas.
Once you’ve got the build-up neutralized, it helps to keep your house dry. No humidifiers!
Also, using the mattress and box spring covers and allergen-proof pillowcases makes a huge difference.
Thanks, Harriet the Spry. I appreciate the leads! This has been the worst season ever!
Dust mites don’t mind some heat but they hate the cold, throwing your cloths in the freezer for a while will kill then dead.