I add a few drops each of peppermint, ylang ylang, lavender, and rosemary EOs to a gallon of water for my final rinse. I used to do a cold rinse, but since it's winter I now do a tepid rinse. I figure it's beneficial enough with the EOs without giving myself the puh-nomonia. I sometimes add ACV, and the EOs help to cut down on the vinegar smell.
I also add peppermint oil to my Aubrey's GPB. I like the extra tingle.
Good post! I always like finding out about new possible uses for the stuff I already have.