That is a nice example!
I have to admit, my big breakthrough in clicker training Jackson(after 7 months of "yeah, OK") was when I got a sample mug of Top Spec Leisure Time and decided it would make a good handy treat. Suddenly, I had a horse who would leave his friends and gallop the length of the field for a 10 minute clicker training session! Lead ropes were no longer required

Apparently carrots are nice, apples are OK, but those little pellets are addictive
The effect has outlasted the Top Spec (it was only a sample) and has transferred to Spillers High Fibre nuts. I continue to find it amazing the effect about 300g of fibre doled out over an hour or so can have on a horse (I'm sure he could get the same number of calories by grazing the same length of time).
I am pleased to say that in moving field a few weeks back we have had no spontaneous recovery of situational behaviours (i.e. refusing to leave other horses at all...) and he is still very happy to go for long, fibre nut motivated hacks