As ever, your heart is in the right place, but... I find a certain measure of flaw in your execution. First, illicit substances usually are the actions of carefully crafted non-lethal (comparatively) poisons, which produce their effects based upon the impairment or misbehavior of some bodily function, so you did, in fact, either drug or poison foals. Both of those are Bad, Twilight. Furthermore, you should not teach ponies to mock others, even in an exercise intended for betterment. Finally, you neglected to inform Cheerilee that you were still under the effects of a decree requiring a second adult presence supervising your behavior around foals, due to your many magical mishaps.