A word of caution when using some ceramic crock pots, the lye can eventually damage them. You could still use it for soap, but not food. As far as Essential Oils, there are really no therapeutic class for Essential Oils, even though many sell as such. FDA is after DoTerra and Young Living. You need to purchase quality Essential Oils from supplies such as Bramble Berry, that is hard for me to say... Liberty Naturals, Camden Gray, and most other soap suppliers. DoTerra, Young Living, and others selling outrageously priced essential oils, purchase from some of these suppliers and re-bottle. A few drops of essentials oils is simply a waste of money in soap. Many use 3%, I usually use in the neighborhood of 5% EO in my 5-6 lb soap batches