Allergen-free yoga props?

Hi to my fellow DYWM practitioners! I was recently diagnosed with a severe dust mite allergy and was wondering if anyone knows of a good yoga bolster that is dust-mite proof? I’ve been using a home-made bolster with rolled up blankets, but am thinking that deep breathing into or near blankets that have dust mites is aggravating my allergies (and don’t want to have to add more regular laundry to my list…ha). Any thoughts or additional suggestions greatly appreciated!