Well I would think it would take more than a single session, because your muscles have been in the misaligned state for so long..

It's called muscle memory,, they will tend to pull back to the old position for awhile.

So you had 1 session and do you feel better or different at all?

I had chronic repetitive strain injury and it took 6 months or so to get the worst issues resolved. 2x a wk , then 1x a week ,then bi monthly then monthly etc..

I will be very surprised if a one time treatment holds..
Just don't sign up for any long term tx plan.. if they try to push that if you go back..