yep i have used kool-aid
but opted out since it had so much sugar and it smelled
fruity when i was done
food coloring took too much, to make it a concentrate that worked
reed dye seemed to work best of all the weird stuff i tried
but i am sure there are other things that work well too ....
one of these days i will try encaustic painting on prints ...
wax and paints seems easy and fun