I do this a lot too, and just one word of warning from personal experience: don’t overwork one spot, or apply steady pressure to one spot for a long time. The former is going to cause a feedback loop of swelling and irritation, leading to more overwork, and so on. The latter just hurts, and impinges on circulation.

For the lower back, I recommend a “foam roller” although it hurts at first, my god does it help.