I have used "GUNK" products for years and they have always
worked for me.
I have now found a new one I would like to recommemd to solve the squealing brake problem!
The "GUNK" product is called "SQUEAL MEDIC" and is sprayed directly on the DISK AND DRUMS. It is apparently a VERY FINE ABRASIVE in a carrier base to remove the glaze on the pads and quiet them.
IT WORKS