I used it to flush my system when switching the Grand Prix from dex to Prestone. Gunk in the overflow bottle made me think the whole system was similar. I drained the dex, filled with plain water, drained, then water with a cup of Cascade powder (green box)and ran for about an hour, drained, fresh water, drained and added Prestone 70/30; knowing a lot of plain water remained in the system.
If Cascade is safe for dishes and glassware, must be ok for a coolant flush that works in a similar manner to a dishwashing cycle.
Always been a little leary of chemical flushes and thought this was a better alternative.