"Bentonite (/ˈbɛntənaɪt/ BEN-tə-nyte) is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capacity than Ca-montmorillonite."

I need a babel fish  Zaphod  :-)

(At least I've learned something new too.)

Yes.  Direct Current.  

Gypsum/bentonite mixes are routinely used for earth electrodes to reduce the contact resistance.  It is a hygroscopic mix and benefits from an initial  good soaking when it is installed.  If you interested I can pass on the  gypsum bentonite mixing ratio.

Well there is certainly no harm in knowing - though if its only a mix of gone-off plaster powder and cat litter then the magical mix maybe  overpriced ;-)

Mike.