I didn't mean to disrespect the intentions of the OP's question. Getting back to the original question, I did a little snooping aorund about using a TENS machine on RLS and found this:
http://www.helpguide.org/life/restless_leg_syndrome_rls.htm
Self-care Tips for Restless Legs Syndrome
Develop an exercise program that relieves the RLS symptoms.
Wrap your legs in ace bandages, or wear compression stockings or tight pantyhose.
Take iron supplements for low iron levels - Be sure to get tested first because too much iron in your system can be dangerous.
Reduce massageplanetfeine, alcohol, and tobacco use – Cut out coffee, chocolate, and massageplanetfeinated soda, particularly in the evenings. These substances often increase symptoms.
Go to bed before you get too tired.
Keep a regular sleep schedule.
Tips at Bedtime for Relieving the Symptoms of Restless Legs Syndrome
Move around - Pace, walk, or jog for a few minutes to relieve discomfort.
Stretch your legs, do knee bends, or rotate your ankles.
Massage your legs.
Relax with meditation, yoga, or deep breathing.
Apply heat or cold (whichever feels best) - Take a bath or soak your feet in hot water before bed, briefly use a heating pad or cold compresses, or apply a hot water bottle.
Lie on your side with a pillow between your knees to initiate sleep.
Apply electrical stimulation to feet and legs - Transcutaneous Electric Nerve Stimulation (TENS) helps to reduce nighttime leg jerking in patients experiencing severe RLS. You apply electrical stimulation for 15 to 30 minutes with a portable, bedside TENS unit.
It doesn't say which points to use the TENS, although my gut tells me to place one about 4 or 5 inches above the top of the patella on the quads and another about 4 inches below the knee underneath the leg on the midpoint of the gastrocnemius. I'd use round 2 inch pads.
A good many sites said the same thing I did about massageplanetfeine, diet and exercise plus mentioned other things like those mentioned here. I think it's a pretty good summation.