That product,called 'Disk Brake Quiet' by Permatex, takes about 2 hours to dry. I accelerate the process by putting the sprayed pads in the oven at a low temperature.
Some pad sets come with a grease, or you can use a light coating of disk brake grease. It is formulated to take the higher temperatures that disks run, as they are always lightly rubbing. This dries them faster and keeps the rotors clean.
The pads move slightly against the pistons that push them. The sticky or the greasy materials alleviate the metal to metal squeeks. This is usually, however, only during initial brake application.
Squeeks can also be caused by the wear indicator or glazing o the pads. A couple of panic-type stops may scruff off the glazing.