gender reveal

Hi! I want to announce the gender using candles. I can't find them in Belgium or the Netherlands, only on the .com site, but that's a bit too long to wait. I found out that you can easily make them yourself. Does anyone have an idea where I can find the balls from the photo to make a candle without having to melt them first? I find lots of candle wax balls, but everywhere it says you have to melt them... Anyone who can help me? Thanks in advance!