There are better,and more powerful things to use,but we always used Cascade in the 855 and 927 Cummins engines for a reason.It leaves almost no residue behind.Working on the A at home isn't a problem to rinse it out,but if you are on the clock for a customer you can't be taking the time to run through a couple of rinse cycles.I like Lestoil in the A.I dump the whole bottle in,(small size),top it off with water,and drive it for a week or two.It DOES take a few rinse cycles to get rid of it though.When it is in there you will smell Lestoil all the time within 5 feet of the car.