> What's a clean, no-mess, minimum-hassle way to offer honey samples?

Even just  toothpicks and a honey squeezer (bear) will work. It really helps
if the beekeeper loads the honey onto the toothpick held by the customer.
This moment creates the opportunity to make promotional/educational comments.
Sure honey sells itself, but it doesn't hurt to encourage it in a
non-aggressive way.
.