You don't need a bloodwood tree to make didjeridu, almost any tube will do. PVC sewer pipe can be used. It is played somewhat like a trumpet, except you are using the entire length of your lips. You are almost sputtering into the tube. After you play for a while your lips will know it.
Large tubes have a deeper sound but take more air.
They have a nice round molded lip on one end. They make a great little didjeridu. Don't take much air to play. Try one, for less than a buck you can't go wrong. Now do it again but breath in and out through your nose at the same time.