I am learning to fly gliders and I struggle with motion sickness.

I have tried:
- Ginder tablets, it helped but I was still a bit nauseaus.
- Motion sickness tablets, they affect my awareness and concentration.
- Chewing various things, best was beef jerky (not a joke) it helps but
still not good enough.

Today in a lesson we had very good conditions, for the first time I was able
to really play and experiment with the glider without stress or time
constraints, various banks in thermals, near stalls, trim various speeds
etc... I was able to get back to thermals to go back to 4-5000ft, I had all
these thing I was planning on learning/improving and today was the perfect
day for it but after 30 min the instructor tried to show me how to thermal
with a high bank and in 2 spins I started to feel bad, I took the controls
again but 1 minute later I was sweating, my focus and concentration were
gone. We had to waste 5000ft gliding straight down with brakes out.

My disapointment was huge, I was upset with myself and questioned if I
should have stayed and fought it but with hindsight I feel we did the right
thing to land.

I understand that I will probably get used to it but from a learning point
of view only doing short flights will slow down my progression and from a
financial point of view, well a 15min or 1 hour flight cost the same...

I have seen some adds about wristbands that look like a watch, they
electrically stimulate the median nerve and are supposed to prevent motion
sickness, since they do not have any side effects and the intensity is
adjustable it seems to be the ideal solution for me, I can gradually lower
the intensity until I am used to it.

Now the question, "do they really work ?" they are not cheap, about the cost
of 4 x 3000ft tow so I would appreciate if someone who used them can
comment.

Cheers
Jack