Unfortunately, even at age 60, I haven't ever learned that when they say less is more, there could be a reason. The Yoga Toes instructions are pretty vague about starting gradually. I figured that when they said to start wearing them for 5-10 minutes, it was to build up to a point where they wouldn't be uncomfortable to wear. Since they felt pretty good from the get-go, I wore them overnight for several days as soon as I got them. The good news was that my toes did, in fact, straighten a bit. The bad news was that after a week, I could barely walk! My podiatrist explained that I was suffering from tendon injury from too much stretching, too fast.
The end of the story is, after a couple of weeks of limping around in flats, my feet did recover, and I started using the Yoga Toes again, this time very, very gradually. I now use them for a half-hour or so most evenings, and they are just great. My feet feel like they've been massaged, and yes, my toes are straighter.
I do believe that they're pretty pricey for two plastic pieces, but then again, I don't know what engineering costs are involved in producing them. In spite of what may sound like a bunch of negatives, I think this product is just great! If anything ever happens to my Yoga Toes, without doubt I will buy another pair!