It's a substitute for anti squeek lube. The alignment is you want it between the metal portions of the adapter/caliper that the pad metal backing plates touches as it is that contact that squeals. Yes mock it up to see where it goes then slap it on there. You do not have to use em & if your pads are quiet you're good. & if they ain't then take em out & stick on the pads. My sliders were incredibly noisy till I judiciously used some DBQ sparingly on the back on areas of contact as needed