Well you can use it anytime.
I would suggest after the PR stage and before activation. That could be just after PR, in the middle of incubation time, or just before you activation session.
I believe, that to get the most benefit you should use it like the other paraliminals. Use it everyday for about a week and then at least once a week for several weeks after that. Gee, that kind of implies you should be doing PR everyday. 
You are perfection.
Iam2 