All essential oils need to be used at a safe %. Some, like orange will always fade. I have the Kevin Dunn book of Scientific Soapmaking. It is an excellent book for soapmaking, but he doesn't go into essential oils.
You just can't use "a lot". Using too much essential oil in soap can make the soap irritating. Just because their essential oil costs are 1 to 2 times the cost of the oils per batch that's pretty useless. You can find reasonably priced essential oils that are good quality and work in soap.
If a soap sat on a shelf for 9 months, that might not be the right market for your soap.
I sell wholesale and they sell much much sooner then 9 months.
I posted a sticky on essential oils. You might find it helpful.
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