When I was in high school I worked for an old timer that specialized in exotic cars ( Ferrari, Pantera etc.) and swore using dishwasher detergent for a clean & flush did a better job on cleaning than anything else you could buy. I used to do it on my own cars (secretly) because it always seemed to work. But I stopped quite awhile ago after thinking about why they tell you not to put aluminum or copper pots & pans in the dishwasher. I assume it's because of the pitting or accelerated corrosion you see on the pans after running through the washer (yes I put the pans in the washer, too lazy to handwash). I related this "caution" about pots & pans to copper & alum radiators and what the detergent might being doing to them. I don't know for sure but I stopped anyway to be safe.
There, now another skeleton has escaped the closet. Used to be young & foolish now old and still foolish.
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" ......Ben Franklin
Ride hard and live long
San Jose built 66GT coupe w/ all the options