Gardening

... "wettable dusting sulfur" at a garden store, or probably any big-box home improvement store like Home Depot or Lowe's.

As for the clothes, I mean "don't be within 20-30 feet of where you put them". Tossing them in the washer right away is a great idea. But if you throw them in a hamper in another room, they are not going to be able to get to you, their mobility is quite limited because they are tiny.

We usually just toss the clothes in the laundry room and wash them when we get to it and we seem to get away with that

It seems like some folks are maybe not as sensitive to chigger bites or whatever, but for me getting really eaten up is total misery and the fact that I'm willing to coat my ankles with creamy vaseline, douse them with alcohol afterward, take a hot soapy scrubby shower immediately upon getting home are all testament to how much I don't want that miserable itch for 2 weeks ever again!