They make a product that is a gel that is applied to the pad backing plates. You simply take the pads off (again) and spread this gel on the back of the pad and reinstall. You can buy it at your local parts store in little 1 use aplications packaging for like $1 EACH. I think the name is BRAKE QUIET or similar. Ask your parts tech at the counter and he will explain. Also ensure you used brake parts grease on the slides the pads slide on. Yes there is a difference in BRAKE grease and you can get that there as well.

Now you did the right thing in cleaning them up and taking off the glaze.