I'm currently working on a 10 Hitpoints account on the side while I do my duties as a server moderator, and there is no current way of leveling up Attack/Defence/Strength without my Hitpoints being touched, so I would love for Pest Control's rewards to offer experience - just as it does in Old School RuneScape. I enjoy creating unique accounts, and having experience as reward from Pest Control would certainly make things more possible to do.
As suggested by others - make it attractable and worthwhile, but not too over powered.