No it's not the Castor that stinks, all I fly are fuels with Castor in it, have since I was a kid. I don't know what it is but it's strong. The smell of Castor is what I expect to smell. I put some coconut additive in some fuel once. Drove everyone crazy trying to figure where the smell came from, not too many coconut palms in Oregon. Nope Castor I like and like you my clothes smell like Castor oil, the wife leaves the flying clothes in the garage. I don't know what it is in PM that stinks so but the wife ain't having none of it so I just stay with Omega normally. We have some guys who fly nothing but PM all the time since Chief Aircraft is so close and we can get a good deal on it. Whenever they start everyone else just walks a couple tables away to get away from the odor.