I love candles and used to use them a lot. After awhile, I ended up with a pile of glasses with a tiny bit of unusable wax at the bottom. I searched for a way to get the wax out so I could use the glasses for other things. Or if you want, you can make more candles.
Old used candles that are unusable anymore
Don’t worry, if the glass was made to hold a flaming candle, it will hold boiling water. Fill the candle with boiling water and let sit overnight. Please note, the water must be cooled completely before removing wax. Stick a knife in the center and cut the wax in half or just remove. Dump out the water. It won’t be empty yet. Use your knife and work it around the edge of the candle in between the candle and the glass. Fill with water again and stick it in the microwave for one minute. Leave the microwave open afterwards to air it out. Let cool again and remove the wax. Use soap and a scouring pad to get the remaining bits of wax out.