Quaternary ammonium salts which are softening/conditioning agents are used in fabric softener as well. So the tie to fabric softerner is not new per se. Diethyl ester dimethyl ammonium chloride can be used in hair conditioners as well.
Conditioner is really a (fabric)softener for your hair. LOL at this smelling like Downy. The only scent I liked from MJs is the buttercream