Ensure any bleach you use is unscented and free of surfactants, for reassurance after your bleach dip you could dip them in a solution of dechlorinator and water.
I did one time find some bleach pils. A solid oill that would resolve in water and turn in to bleach. It didn't have surfactants. Another option is chlorine monoxide water purification tablets sold in hike equipment stores. It may take several tales per gallon to get a strong enough solution to do the job. Chlorine test kits and strips are available at aquarium supply companies and some aquarium test kits contain chlorine test. Make sure the label says chlorine and not iodine. The link below are chlorine tablets
https://www.rei.com/product/695229/katadyn-micropur-purification-tablets-package-of-30