Hi,I havn't tried BB's shower gel but I have used Organic Creations Goatsmilk and Shea gel,actually I dilute a paste so I can achieve a super thick shower gel,what I have found is some FO's will turn that thick gel to thin liquid in two seconds ,others will actually thicken it up more,as it is much easier to have a thicker gel than try to thicken a thin one (trust me)
I will from now on TEST a small amount of FO or EO in a little gel to see what it will do. I guess after reading alot about this ....it seems to be a problem when fragrancing liquid soaps and shower gels.
Good Luck PS I have had to resort to putting my gel into baggies and pipeing it into containers....it works