I agree grenades can be a pain to level....but if there were an active invincible glitch, why bother? There is absolutely no challenge when doing so. That's like fishing from an aquarium tank with a net (which is still probably harder....lol). Just my opinion....
KingsHead is a great place for grenade leveling. Make sure you use stink pot, smoke and fire grenades to get the most rep. I've found only having one point in each grenade skill and using the rest in passive gives the most rep. The less damage you do, the higher the rep. Mix up what you toss and leave the standard grenade as a last resort.
irate3: