Do you have a source for why you think it will help fragrances stick in soap? I don't think it will. You can use PS80 in LIQUID soap to keep the fragrance from separating out, but in CP soap the fragrance isn't going to separate unless it's poorly mixed it. The fragrance will still go through the chemical reaction regardless of what you add to the soap.
The first thing I would look at is if you are using enough fragrance in your soaps to begin with. (I apologize I don't know how long you have been soaping, but see that you joined the forum less than a month ago, so I am assuming that you are a new maker) Often new soapmakers will not use enough fragrance either because they do not know about IFRA usage rates, how much fragrance is really needed to scent the soap, and/or because fragrance is expensive and they want "more bang for the buck" [to make something expensive last as long as possible].
Some makers, depending on their recipe and the quality of the fragrance, may find that adding clays (usually white kaolin) will also help with scent retention. I've found it helpful when working with EO's but not a longterm solution.
