Hi @mpmurphy
If your thigh cramps are as unbearably painful as the calf cramps that have me jumping out of bed in the middle of the night, I can't even imagine enduring for 20 minutes. After 20 seconds, my leg will hurt for the next 24 hours like I overworked at the gym. I can't even speak those cramps are so painful. However, I can get them out by standing or jumping on my foot to push my toes back toward my shin. I get occasional cramps in the back of the thigh if I bend my leg too far back. Very painful, but again, I just have to stand up on my straightened out leg to get rid of it.

I do get some less painful cramps in my shins and ankles that still get my full attention and keep me from sleeping, but no way to work out those cramps by just changing positions. That's a problem. For those, I can use something similar to the Thumper sports massager ( I have a 35 year old Walmart version). I crank it all the way up and it stops the cramp in 30-60 seconds. I'm not sure how fast it would work on intense thigh cramps or calf cramps. Read reviews on all the models out there as a lot of people are using this and similar models for painful cramps during the night. It might be worth a try. I noticed one cheaper brand someone commented that it wasn't powerful enough for tough cramps. Search cramps in the product reviews or Q&A on Amazon and you'll find a lot of people using these for night cramps and their thoughts.

I've recently thought I should try using it on my leg muscles for a few minutes before bed and maybe that would relax my leg muscles and prevent night cramps in the first place.

You'll hear lots of tips for prevention on here, but everyone gets leg cramps for different reasons. You may need to test out all the suggestions until you find one that works for you. I get cramps mostly because of a rare neuropathy I have. Aside from that, I've noticed that too much salt or dehydration will also trigger them for me.

Best of luck to you! I feel your pain!!!