My recommendation is "don't." I think it's exactly wrong for your stated goal.
I did the American Flyers thing years ago for PP ground. I'd been studying on my own when a friend signed me up for the AF rush course as a gift.
The compressed format gives them no time to do anything but teach to the test, which kinda misses the point already, but it was worse than that. By the end of the first day a good percentage of the students were in a daze and it just got worse. Because of the pace, and the fact that people were falling behind, many of the students developed a sort of defeated air and by the time testing started the group anxiety was contagious. It really wasn't fun.
Maybe my class was atypical. And this isn't a knock on AF, they were professional, did their best, and their collateral material is pretty snazzy (I still have the binder somewhere). The staff was actually really happy when I passed... someone made a comment along the lines of, "we're not supposed to talk about this but you are one of the few passes we've had so far...."
The problem was that I didn't pass because of their course. As I said, I'd been studying on my own and knew a lot of the material. That's where I think it's a decent option. If you already know the material pretty well (70% or better), and you don't have test anxiety issues, it is an OK final push cram and pass approach. I scored 95% which ain't great but wasn't shameful either...but I think I would've passed (with a lower score) on day 1.
I don't have test anxiety issues (almost the other way around... I have to force myself to take them seriously...I usually think, "it's only a test, not the real world" and that's not the right attitude if you want high scores) so I can't really help much. I think the online practice test sites would be useful though.