this was my first attempt, but it didn’t work unfortunatelyIt's hard to roll one's eyes while laughing but I definitely did it while watching that video
Instead of rigging up your own fuse, you could probably splice together the red constant and yellow momentary wires to your aux switch wire so that it uses the factory fuse for the switch. I assume that would work but, disclaimer, I've never studied the circuitry of an electronic horse.
Here's how I'm using Aux 6: https://www.boomblasters.com/product/horse-sounds-car-horn/
Very easy install, there is even a bracket on the front of the battery that serves as a great mounting point.
I simply zip tied it on there, ran the red wire to the battery, black wire to a negative terminal on the body, and the yellow actuation wire to the yellow/orange aux 6 wire. Now everytime I toggle the switch, unsuspecting wranglers get this (Sorry for the shaky video):