When I first saw this effect, I was mystified and intrigued. The chocolate velvet finish is matte and fuzzy looking. It really highlights geometric edges compared to glazing, which tends to smooth things out. There are spray cans available to purchase, but the spray quality won’t be as fine or versatile as if you use a sprayer gun.
This process is the same if you have regular chocolate or sugar free chocolate. You will want to set up protection in the spray zone, as this will end up everywhere! I tape up plastic wrap and use a box. I also wrap up my one and only rotating cake stand. When finished, spraying, flush the sprayer well with warm water to minimize cocoa butter hardening inside the gun. This goes without saying, but the gun will be dedicated to food applications – no switching back and forth with actual paint! I have seen some discussion questioning if a paint gun is food safe, but since you are using melted chocolate, the working temperature is much lower than what might cause leaching of plastic components. If you are very concerned about this, there are specialty sprayers available for the serious pastry chef.