I contacted Jackson Manor about the same candles, they said they used both real and fake. The way they do the fake candles is to get a piece of clear hard tubing, then drip wax at the top to create a melting look, then paint. I'd love to try and use real candles but hollowing them out seems impossible, and you'd have to store them in a cool place so they didn't melt.
Maybe get some clear tubing and dip it in wax? That could work.