If you are using an essential oil, make sure that you do NOT over use it just to get a specific effect, or even in general. Over use can be dangerous. It will depend upon which eo(s) you use, but the average dilution rate is no more than 3% of the total batch. Strong eo's though are almost generally 1-2% max. Not only do you need to worry about the eyes, but you don't want any whohaws burning! And, let's face it, when you are showering, most people would not remember to "not" use the bar to wash their face and their private parts. So make sure you check the max usage rate on each eo you consider using. And by the max usage rate I do not mean the fragrance calculator on a vendor site, I mean the IFRA usage rate (
www.ifraorg.org).