Hey Joe; I still have the barrel I bought in 2013 for my first RMH.
It is off to the side and out of service now, but it was in seasonal use until 2025.
It could be installed today and put back in service. They do not wear out.
Can you use full barrels rather than split ones? Sure I guess so.
Although the extra-thick cob at the bottom would not heat up, the thinner side covering would.
Paint removal is not bad at all if you are in a location where a wood waste burn barrel is allowed.
With one good burn, 2/3 of the paint will be gone; then you burn a small fire and leave the barrel tipped on its side, rolling it as the paint comes off.