The kilt hose I own are mostly a Merino wool blend, but I do have some 100% wool, as well.

The 100% wool hose are great, and in general I prefer 10% wool for things such as my kilts and jackets. But I have no problem with a blend in hose. Here's why.

My 100% wool hose are not as comfortable. Not that I find them uncomfortable, mind you. But some people are more sensitive to wool than others. You may find them a bit itchy on your legs and feet, especially when they are new. I find that washing them with a bit of conditioner helps this a lot.

My 100% wool hose are hand wash only. Period. No exceptions. I hand wash them in cool water and allow they to dry flat.

By contrast, my wool blend hose are easier to care for. Different blends will have different qualities. I wear hose from House of Cheviot which are about 50% merino wool (very soft), and 50% man made fibers, mostly acrylic with some nylon. These are super soft and very comfy to wear. I machine wash them in cool water on the delicate (gentle) cycle. I let them air dry on a drying rack. And they do just fine. I've never had a problem with anything shrinking.

I mentioned that different blends will have different properties. I have in the past worn hose from other companies that were labelled as an 80% wool blend (the other 20% presumably being an acrylic/nylon mixture). They were advertised as machine washable. I washed them just as above, in cool water on the gentle cycle, and let them air dry. After a few washings they shrunk to the point where I could no longer wear them. So I would advocate hand washing anything you see labeled as an 80% wool blend, just from my experience.