soapmaker here. While lavender oil is nice to have, its also rather cost prohibitive in what i believe would be a compelling dose to elicit this type of response.<p>as for tea tree oil, im in favor of phasing this out entirely as it seems to serve no real purpose in cosmetics and is actually somewhat toxic to humans. Its had a number of folk remedies, such as a cure for syphilis and a tincture to reduce boils, but none of these have succeeded in scientific testing.<p><a href="https://en.wikipedia.org/wiki/Tea_tree_oil#Safety" rel="nofollow">https://en.wikipedia.org/wiki/Tea_tree_oil#Safety</a><p>most cold process soaps will fragrance at 3-5% the weight of the actual oil. I can speak from experience that 5% tea tree oil soap is vile. The final product emerges with an acrid fragrance not unlike pine floor cleaner, and each bar is brittle enough to crack if dropped. many crack during the curing process, and the final product has a texture similar to the gear shift on a cheap car.