Yes, I have tried Shock wave therapy. I don't know if it was Extracorporeal.. It was called Shock Wave Therapy and he pounded my feet with some device.. didn't hurt at all.
One other thing, try this everyday. When you get up, no shoes, stretch your feet by doing a lunge and go forward leaving one heel totally planted on the floor behind you and stretch that heel out (the heel in back of you) and you pull your body away from that heel and put your weight on the other heel. Just like a hamstring stretch but you are stretching your heels instead. Stretch it a minute or two and then do the other one. If there is pain in your heels, then this can help stop the pain. Do this every morning as soon as you get up and several times a day when you get up from a chair. Try to feel your heels stretch flat and long. See if that helps.
I had this when I was younger. I know the pain you are going through and what I did to get rid of them for good was I used a foot file and filed away my heels until it was soft, even if the sores hurt doing it, and I soaked in a hot foot bath with a cup of epsom salt. I used lotion on my heels after that. I kept my feet soft and filed anytime I saw any callous buildups and did the foot baths and lotion afterwards. So keep your soles soft and moist. Don't let them get dried out. They went away for good. Also to this day if I feel my feet building any callous layers, I get the file going.
Also it is CRITICAL and I stress that so much that you only buy shoes that are well made with excellent insoles. My theory is bad shoes are the main cause of it. I make sure my shoes are well made, not cheap junk, and are well supported and I have been free from Plantar Fasciitis ever since and that was over 11 years ago! So there is hope!
Have you tried Extracorporeal Shock Wave Therapy?