Gooood question. Honestly when it came down to using charmed pets and jug pets for soloing exp, I chose charmed pets. There is about 2 reasons why, most likely more but I'll only mention 2. For one charmed pets (DC-EM) are normally stronger then jug pets, I don't know why, maybe because SE just doesn't like BST too much or something. 2) Jug pets just cost gil to use, I would rather just charm and use pets for free other then spending on jugs that are not even as strong. (I guess this would also would apply to number one) Jug pets seem to have a harder time holding hate and snarl is not even useable till around 40 something (I think) so expect to get hit alot more. Of course charming pets has it's flaws, pets being too far apart, some pets being T, some pets has resist charm, and the biggest flaw that causes the most deaths while leveling BST is the misscharms. Oh yeah... those are fun, good times.. good times... There is the chance of your pets losing the charm affect which also kills you, but you can easily avoid that if your careful enough.
As for exp, jugs are pretty much the way to go unless you can find a pet around ya.