On Monday I posted a craft using some recycled Glade candle holders decorated with alcohol ink. Well, this is how I cleaned them out.
Step 1: Put in freezer and forget about them (the forgetting is optional)
Step 2: Take out of freezer and grab an old butter knife. Pop wax out.
Step 3: Run under increasingly warmer water (or let the glass return to room temperature and crank the water to hot right away). Once the hot water has softened any remaining wax, use a paper towel to clean and polish out the candle holders.
Step 4: Admire your work and decide what to do with your clean candle holders.
Putting the candle in the freezer helps to solidify the wax and helps it pull away from the edges of the glass. This method doesn't work as well for those candles you have burned down to practically nothing...but it did help keep the tiny disk of wax together as I scraped at it with my butter knife, so it's a helpful step to freeze them regardless. The candle above that had a fair bit of wax in it, popped right out.