By pulled the caliper you off you just mean unbolted from the knuckle right? Dust seals off, pads in (or a wooden block, whatever) so the pistons don't push all the way out... grease them up. Seals back on, bolt them back up? The line is plenty long enough to rest on a foam mat on the ground if you pull it off the little "keeper" on the knuckle. That means little to no brake fluid mess then, hopefully?
If so I might try to do that next weekend. I haven't ordered the part for the RPV's yet but I will this week.
If you're going to install the RPVs anyways, why not just pull the pistons out completely as you'll need to rebleed everything?