As far as I've seen, TriBot has a fight cave script for melee training.. Otherwise you can just turn auto retaliate on and stand in the middle of the cave and the rest is done for you.
Crabs or experiments will be better xp/hour though.
Train on Experiments, Rock Crabs, or bot Fight Caves, which is going into the lava place in karajama and repeatedly doing the minigame for lava cape and continuously die. (you dont lose items)