Hello Fred, I'll pile on here. This sounds like a product you use to seal a leak, re-establish cooling, and sell the car fast!
I'll agree with those who do not recommend the quick fix. "Good things aren't cheap, and cheap things aren't good."
BTW, I had to have the evaporator core replaced in the Audi last year for the best part of $2k. And, I never knew there were so many parts to the dasboard, or that they'd all fit in the back seat (where the Technician put them during repairs)
'96 E300D 58k mi (wife's daily ride)
'95 Audi 90 118k mi
'92 GMC Suburban 138k mi
'85 300SD 230k mi (my daily ride)