Making the Sathar creepier; or the Worm Inside

What if they put an immature worm 4-6 inches long down the throats of prisoners to grow inside ala Alien? Of course the method of doing this to drals and vrusk is different. Or dral and vrusk characters are immune to it. <div><br /></div><div>They also use hypnosis to make the victim forget the experience although they may have nightmares about something growing inside.</div>