As arcologist said, the oil is very strong. Sometimes, i add dried spearmint or mint to a changa mix, and that little addition can be nice.... But too much and it is a little over welming. If you are going to use the oil, no more than one drop. I'd suggest using some freshly dried mint from a garden rather than the oil, though. That way it adds that crisp addition of flavor, but not ruin the batch. Also, freshly dried lemon balm is great, too!

Sometimes it's good for a change. Other times it isn't.