W.H.
Havent tried with my son (he's 8 and I was *just* thinking the other day that it was time to teach him to swallow pills, so thank you for asking this question!)
I personally had a VERY hard time learning how to swallow pills and only because I absolutely had to when I had an infection around 11-13 years old. It was only the very last pill of the prescription that I finally could do it! :-(
To this day, I still have to tuck my tongue under the cup and then drink fast before my tongue "traps" it and keeps it from going down. (dunno if that makes any sense... but it's what I have to do...) I can and do (with a little effort) swallow pills like aspirin or small allergy pills without water now though. Only been what, 30 years for me to learn how, LOL.
Practice with mini M&M's - good idea.