@varshini29,
I'm also a relatively new CP soapmaker so I don't have alot of experience to offer. (26 batches - I have basics down but there is so much to learn ...)
So far, I've only used clays to create a pencil line in my soap. Like you, i found EO's to disappear in my soaps. I assume during saponificaton? Now, I save my EO's for if I make a M&P bar, since the M&P base has already saponified and I feel like what I smell going in is what I get after soap cools.
In terms of knowing how much EO to use, what I learned early on this forum is that what is SAFE to use is different than how much to use to have a strong scent. There are IFRA guidelines for all EO's and FO's. The IFRA guidelines tell you what is considered SAFE to use for any given EO. Some EO's can be irritating to the skin. Some FO's also have ingrediants that are irritating, etc. to the skin,
Early on- after I'd only made a couple batches of CP- I asked on this forum if anyone would exceed the IFRA guidelines. According to IFRA guidelines, my favorite EO, lemongrass, can only be used at the rate of 1%!! I had been using it in my M&P at the rate of 3%
In response to my question, I got an extremely resounding NO, NO, NO, a thousand times NO!!!
I make soap as a hobby. I give it to family and friends. No one had reported a bad reaction to my 3% lemongrass. But since then, I understood the importance of IFRA guidelines and following them- even as a hobbyist. I count myself lucky that nothing terrible happened.
So, I would encourage you to use an app like EOCALC to figure out what percentage of EO you should use for any given EO. EOCalc is free to use and can be found at the following link.
https://www.eocalc.com/enter-your-own-blend/
Since EO's tend to burn off in CP (in my experience), and are pricier than FO's (in my experience), I use almost exclusively FO's in CP. (I realize some people, especially those who sell, prefer EO's for an all natural product) . Before I buy an FO, I check its IFRA rating. If it's below 5%, no matter how great the price or its elements sound, I pass on it. So, check out EOCalc if you haven't already done so.
As far as clays, as I said, I've only used clays to make a pencil line in my soaps (although I've bought several clays I intend to use at some point. ) But, based on my reading on this forum and generally on the internet (I read alot .... ) the consensus is that clays DO help stick a fragrance,
I did a comparison this past summer of colloidal oats v. ground oats to see if there is a difference in the exfoliating, soothing, etc. qualities of the oatmeal. What jumped out before even using the soap was that the ground oatmeal (which was not chunky but not ground quite as fine as clay ) retained the scent in a big way. In comparison to the colloidal oats which are ground so extremely fine they are not visible in the finished bar.
So, some additives do help stick EO's and FO's. I would say that clay, in addition to other qualities it might add to your bar, will help stick your fragrance.
I hope this is helpful.
