Thanks, everyone!
I have plantar fasciitis and wear my
crocs all of the time at home. I've worn them on local weekend trips and have never had a blister. Then, I took them to WDW. My PF was great! It didn't act up even once. But I got 2 blisters.

That was totally unexpected with my crocs. After the blisters, I switched off between the crocs (PF support) and Tevas (a little better for my blisters).
Both of my kids wore crocs. Ds had no problems at all. Dd developed one hot spot (not a blister, though), on the top of her foot where the shoe rubs against your foot. I used Body Glide on her and had her switch to Tevas for a day. She was fine after that. She did finish up the trip with crocs.
Now that I'm home and my blisters are healed, I'm back to wearing my crocs. No blisters, and all is well with my feet. I do plan on wearing my crocs to WDW again. They are great for PF, and other than the blisters my feet did not ache for the whole trip. Next time I will use Bodyglide all over my feet with the crocs.
I discovered that the first aid stations at the parks will give you moleskins and band-aids if needed.
Here is a picture of us with our crocs:
Notice my lime green Baggallini. I love that bag!

It is just the right size for bringing into the parks. And it was comfortable to wear. On
MNSSHP, I switched over to a backpack and that was so uncomfortable. I was glad I had to use the backpack for only that one night. I'll be bringing that Baggallini to WDW again!