Those engine flushes worry me. To aggressive a cleaning for me. I have used three cleaning rounds of the AUTO Rx. Frank recommends two cleanings in vehicles over 100k.
The first two were in my 97 F-150 and I did not notice any changes. Though dissection of the first oil filter revealed a lot of crap that had come out of the engine. The second filter awaits my attention.
The third bottle I used on my wifes 97 Saturn SL-1. Within 300 miles of the application my butt dyno told me acceleration is much improved. Oil consumption may have dropped, but its way to early to tell. Last weekend I started the rinse cycle on the AutoRx and will run a second AutoRx cleaning on the Saturn when the bottle arrives.
The stuff works. Don't let the $24.00/bottle scare you. If you look at the AutoRx page you can get a $6.00/bottle discount if your a member of an oil discussion group.