Updated: Jul 13, 2020
The Double Boiler
For stubborn leftover wax, the double boiler method is a great option. This method works by filling a bowl with boiling water, and gently sitting the candle container it it for a few minutes. The heat from the boiling water will transfer through the sides of the container melting the wax left attached to the inside. Once the wax has softened, carefully remove the jar from the water and pour out the melted wax (not down the drain). The jar can then be washed using warm water and soap to finish.
First remove as much of the leftover wax as possible using a spoon. Then, just fill the container with soap and hot water from your tap, let it sit for a minute, before gently scrubbing the inside clean.
Remove The Wick Holder Once you have removed all the wax, don’t forget to take out the wick holder. If its stuck down, just slip a spoon underneath and pop it out. A little boiling water will usually help if it doesn’t want to come out easily. Note: Try using a hairdryer on a hot heat to loosen the wax before using an old chop stick to scrape the wax out. Great as a quick method of cleaning your Jars.
A word of Warning
The glass containers can be fragile, so we recommend hand washing. It’s slower, but you're far less likely to break the jar.
No Drains Never put the wax melted in water down the drain. It will cool and solidify, and probably end up clogging the pipe.
Don’t Overheat You should be careful not to overheat glass containers. There is a risk that the glass will crack if the jar gets too hot.
Don’t Microwave Never use a microwave to melt wax inside old candle jars. The wick holder that holds the candle wick in place is made out of metal, which could not only ruin your microwave, but start a fire.