Yoga.
No offense, derby, but I have heard scoliosis patients advised to forego spinal adjustment. Apparently some danger involved. Cool it worked for your friend!
I have moderate scoliosis, getting worse. Each year of riding I think might be my last. I have raised my seating posture and also wondered why I didn't do it long ago.
But I'm 55 and did pretty well with it until maybe 5 years ago.
I am a candidate for fusion (multiple herniated discs, facet arthropathy and stenosis) or a titanium ladder and have put it off as long as I can. I have begun to collect the names of neurosurgeons. It's a long, long surgery with questionable results---mostly for the desperate.
I purchased not long ago an inversion table, a nice one. It felt good, no panacea, but I boxed it back up to save space. If you ever consider that, let me know. Traction, like chiropractic, is controversial for scoliosis.
I do hang from a chin-up bar in my basement, or from branches on the trail, and that gives some good temporary relief--recommended. I do crunches each day and mild floor stretching along with them.
I also jump rope, but I am addicted and hesitate to admit it. I can justify it if pressed.
Swimming is great! Long-term, to avoid where I am--yoga. It might not be too late even for me.
http://www.yogaforscoliosis.com/
Best wishes!!