I've worn it twice. for example every three months. I forgot how many blisters I had the first time, so I took them on vacation and totally messed up my feet the whole trip. Wore them first night and was limping with blisters on heels and also woke up in pain at night. Try grinding your bubbles on the beach. Be sure to wear socks with them or pay the price. (Unfortunately I didn't want to wear socks. Oops!)