Lubegard Engine Flush is a 15 minute flush product, but interestingly, has a >400°F flash point. The web page doesn't give much more real info, except to tell us how wonderful it is.
This engine flush is evidently very different in its cleaning action from Auto-Rx with its 500 mile cleaning process.
Lubegard's transmission and gear oil additive products have a good reputation--now they're getting into engine oil additive, coolant additive, and other stuff. (I think I'll try their brake "Squeak Relief" stuff on my Volvo brakes--might quiet down the brakes and the Mrs. concurrently!)
Ken