Yeah, google lost wax or investment casting supply to find it. The investment is an alternative to sand. It is a very fine powder with fiber reenforcement and will faithfully reproduce the finest detail.
Using a “flask” and a “sprue base” the wax model is attached to the base and placed in the mold container, the flask. After mixing the investment you vibrate the slurry to help remove air bubbles.
Holding the flask at an angle (best done on the vibrator) slowly pour the investment into the flask so that it creeps up around the model. That also helps prevent bubbles from attaching to the model.
Let the investment setup and slowly heat the flask first to drive the remaining moisture out, then raise the temperature to melt out the wax. After that the temperature is increased to completely burn the wax out (somewhere around 1,000-1,200 degrees F) and then lower the temperature to around 800 (depending on the alloy) for casting.
Unless you are after the adventure of the experience, there are companies that will produce your piece from the wax model.
If you choose to pursue the task I strongly recommend you do enough reading to be comfortable and prepared for it.
Good Luck! (and be sure to share the adventure and results with us!)
Edit; painting the first layer of plaster on is a good method also as Steve said.