I use Joy Wax too, and I've never had a sink hole. I am going to find a different container wax though because there is to much soot with Joy Wax. You should probably go to Natures Candles and they have the instructions on their site, and it will come out perfectly. Two scents that work awesome with Joy wax is Peaks Moonlight Path and Pink Sugar. But some scents it just doesnt throw well with. I use 1 oz a lb with Joy Wax.