Sanding is pretty rough on a launch rod considering some rods are now made of aluminum. Most use a very fine steel wool to clean them off followed by a wipe of spray silicone.
On my home system I wipe off the rod to remove any exhaust residue. Some fine oil is dripped into a paper towel and the rod gets wiped down. I've used the same launch rod for years and hundreds of launches.
From TRF, Neil W posted:
For a very un-scientific test, I tried sliding an old rocket over my old launch rod. There was very minor roughness felt.
I rubbed a scrap of wax paper down the rod then slide the rocket on the rod again.
The rocket slide was smoother on the rod!
Who knows, maybe the wax from the was paper might help prevent corrosion or help seal a steel rod from rust. The waxed paper is now in my range box.
EDIT: Neil W sent a link to the original TRF post from Hornet Driver:
" . . . far as the problem of binding goes, I oversize the lug just a bit so it slides smoothly but you just can't beat a nice true rod to solve that problem. I do like to polish my (launch) rod with a handful of wax paper. It keeps the oxidation down and smooths out the