The tactic's pearl quest itself is a fairly good way to get exp for your NPC. 5700 exp per week (if you kill 30+ mobs [including TW mobs] and touch all 5 ???s before ending the quest). Obviously you're looking at 10 weeks if this was the only time you gained any exp for your NPC. But, if you never call your NPC, then why do you need to level it?

You can also get ~1k exp from scroll from NPC in Ru'Lude every 10k bond points.