My way to test a suspicious fragrance was to take a small vial such as a dram bottle if you happen to have one and put in a small amount of lye solution, then put in a few drops of your fragrance. It will immediately thicken if it is a soap on a stick fragrance. It can even indicate if it is going to rice. Do use enough to be able to somewhat determine how the fragrance may react with the lye. While it is not a guarantee it really helps indicate a very naughty fo.
Other than that I would do what Dibbles does other than keeping my fo in a hot water bath. Another thing you can do your first pour is work with one color until you know how this fragrance works, if it goes soap on a stick just cover your container, walk away for a while, and check periodically, for saponification to begin, (batter heating up). Once your batter loosens up stir and quickly pour. Your soap will turn out more like a hot process soap without going through rebatching. You have to do this quickly because your batter will reset pretty quickly.
If your fo just traces quickly it can be an advantage if you want to create layers, you split off your color layers and only add your fo to each color when you are ready to pour and wait for your fo to accelerate trace.