It's the pin one that should be ok for the pistons and seals, it's lithium soap based glycol grease (as per manual). I've just been giving my front brakes a looking at and the pads were quite a job to get out, sticking on the pins ( which also needed a good whack to shift them) and the sides in the caliper, so I've given them a good clean up and coating with the clip one. I'll have a go at the rear calipers and see how the slide one performs. Red rubber grease is ok, but it does go hard over time and silicone isn't that good at stopping corrosion. Seeing the price for a tube of the lithium glycol stuff, I though I'd just give this a go. It'll be interesting to see how it holds up.