Have no suggestions for you on picky horses,
although I own one.
When out first family of kids were elementary age,
I brashly promised that if anyone got less than a C on his/her report card, the
TV was going to the barn. One of the boys did, and for several years I had
a daughter's report cards on our refrigerator door. With TV (B'c and C's)
without TV (all A's). That TV is still up in the barn.
We do have TV now, but those kids who were raised
without TV use theirs only to play movies on special occassions. No cable
for them.