From time to time, I am plagued by sciatic pain. It was particularly bad, pre-hip replacement.
One of the ways I alleviate that aggravating, ever-present pain (in the butt) is to use a tennis ball. I find a spot that hurts, usually in the glutes, then place the ball there. I either lean against it or sit on it, dependent on where it is. I've found that this helps to lessen the pain; the pressure seems to interrupt the signal. Perhaps because I'm now focused on that uncomfortable tennis ball?!
Another good use for a tennis ball is to place it on the floor, then gently roll the ball under the arch of your foot, towards your toes. This can be a challenge. Not because it's difficult to do, but because my dog thinks it's playtime.