This is really cute.  I've filled it with honey, which does not crystalize.  I'm not sure I'd like it if I used any other type of honey.  The dipper may get stuck in the crystalized product and pull apart if you were not careful.  It would be easy to heat in the microwave, I think.  Although I'm not sure if the glaze contains anything that might make that a problem.  You could definately heat it up in a pan of simmering water.  I'm not sure I like the wood handle on the dipper.  It invites contamination over time.  Not everyone in my house understands that the dipper does not go in the tea.  The kiddos have a tendancy to stir with it which means it will be in the dishwasher regularly.  We'll see how long it lasts.  It will be a simple thing to replace the dipper as needed.  But it probably won't be a match, if that's important.