Originally Posted by Darth Saruman
Anakin could use force lightning after training but when he lost his other hand he could not ever do it.
Technically you don't need a hand to shoot lightning, a tail or feet or something else would work also. Si technically he can shoot lightning from his stumpy limb.
The thing being the arms and legs used to build Vader's tincan interrupts his ability to use Sith lightning. As for shooting lightning from the mouth/nose/weewee/etc, thats too much anime watching. Star Wars characters does not go "chargin' mah' lazer" and blast beams off their mouths.