My feet sweat, so there will always be a small amount of damp in my socks. I use Hydropel sometimes when I know I will be putting in the miles (more than 10/day). Have not used a second sock in a long time.

Another factor is conditioning. Walk/hike a lot and your feet will learn to tolerate the friction. That and a good pair of shoes that really fit, no blisters, no soreness.

What will give you blisters is heat plus wet plus friction. On a route with 10 creek crossings in about 75-80F temps, I started just wading through instead of bothering with water shoes. Water ran out of my trail runners like a sieve each time. I didn't get a single blister. My shoes fit me very well, and the cool dousing felt pretty good.