That's the best way, because of the proximity of the Save point. You can also try Tower runs at Yen Sid's place. They are easier to kill and often come in groups of four, or more, but if you don't have enough bars, you won't complete the run and therefore, must spend time to recharge it.

If you don't know how to go to Yen Sid's Tower again, go to the train station in Twilight Town, near "The Usual Spot," and it should take you there with a Reaction Command.