I think being CSIP certified would be more valuable to you as an instructor than doing the access program. The way I understand it with the access program you're owned. You might be making ok money, but you're only flying with the owner. If you're trying to build hours that probably wouldn't be the best way to do it.
With CSIP, you could be doing anything from new customer training to insurance stuff. I know a couple guys that did it and have made a mint. Might be worth persuing this option, especially if somebody is footing the bill.