As @mr2martin states...this is very easy to do.
Thus, it's an effect that beginners can do!!!
You're going to want to hand out chocolates to the kids, adults, whomever...so, buy extra bags of real candy to have treats available at the end.
It's easy to switch 'em in.
Candidly, it would seem odd to me to do this type of an effect without a giveaway treat.
Yes, I go thru lots of small candies ;-)
Oh, as@JStuff mentions, you can change the wrapper...
Best wishes...