Rusted rear caliper slide pin question

Serviced all my caliper slide pins and found one on the rear that was seized due to what I guess is rust + some kind of buildup. The pads are at least double the width of the rest of the car, so I know the brake wasn't being activated. Broke the slide pin free and then sanded off most of the rust / gunk that I could see:


Then, liberally applied grease and began to work it back into the caliper. At first it felt like a sandy grind when working it in and out (maybe that's rust on the inside of the caliper?), but it seems to function decently now. Not as perfect as the others, but it moves. Is this okay to use for a while?