Piss taking aside that is soooo wrong Mark, which is why there are so many calipers/pistons that get corroded before their time and so many seals rot prematurely.
Once you have properly rid yourself of any corrosion, and with most under maintained calipers, that's a fair bit, you must generously coat all the rubber bits (seals and dust covers) with red rubber grease. All the metal to metal bearing surfaces eg pins, back and sides of the metal parts of the pads, should be coated with copaslip.
If you are sure that the seals are OK when you strip them, leave the seals soaking in brake fluid until you are ready to re-assemble, then clean them with IPA and then coat with red rubber grease. You should never use ordinary grease on any hydraulic parts of a brake system.
Regular brake hydraulic fluid is hydroscopic which means it absorbs water. You should put a 'barrier' of red rubber grease around the brake piston seal to keep the water which is initially, 'held' in the fluid, out of the groove that holds the seal. Any one who has stripped a caliper knows that most corrosion starts in that groove, which then flakes and pushes the already hardening seal harder against the piston - net result the brakes don't work anything like as well as they should and ultimately if you need 90% braking and you only have 60% then
YOU DIE 
I know this sound melodramatic ... but I've always been a biker and I have lost 5 friends to motorcycle accidents and quite a few to the lifestyle ... how about you?
By the way once the dust seal is coated in rubber grease it'll piss on, with only gentle massage from a bikers fingers
Who needs KY ... thinking about it I wonder if it's the same stuff ... best recommend it to some gay mates and see what they make of it
I've always found the best way to clean all the corrosion out of the seal groove is with a narrow wire wheel on the Dremmel, but keep it well clear of the cylinder and piston bore faces.
Mark, is it me or is your missus finally letting you assemble bike engines on the sitting room carpet ... if so you're finally ahead of me!!! CB still make a fuss of me cooling welded bitz in the kitchen sink
Best I send her down to Mrs P for educating
)...
) cleaning them out.... even though I did my best to seal the cases & barrels, some dust/grit still got in 
