They sell Didgeridoos here at the local Renaissance Fair, King Richard’s Faire. Because, of course, Australian Didgeridoos were so popular in Renaisssance Europe, after all.
Nope, no problem at all. Mine was made from pvc-- it was melted and twisted a bit into an interesting shape, but pvc it was. And I don’t think I used black beeswax either-- just the regular stuff. Sounded fine to me.
Here are some instructions for making a PVC didgeridoo:
Unfortunately a lot of the image links seem to be broken right now. You should be able to follow the instructions anyway.
I’ve made a couple of didgeridoos out of PVC and they work great, and they sound similar to the real thing. The key does seem to be in the deformation. According to the site, this creates the correct level of back pressure to mimic the sound and feel of the real thing. But you can get by with a straight pipe, as long as you have a good mouthpiece.
In order to make a mouthpiece for a didgeridoo, you need to figure out some way to go from a 2-3" diameter pipe to a smaller opening, about 1" in diameter (depending on the size of your lips). Traditionally, this is done by plugging one end of the didgeridoo with wax until the opening is the proper diameter. The mouthpiece needs be a little convex so that you can fit your lips into the hole without bumping your chin or nose.
The easiest way to do this with a PVC pipe is to cap one end with one of those rounded end caps, drill a hole into the center of the cap, and then use sandpaper to smooth the edges of the hole and widen it to the correct shape (it should be slightly oval, to match the shape of your pursed lips). You have to experiment a little to get the correct size and shape of the opening, but once you have it, you’ll know.
How do you make the didgeridoo play different notes? Are there holes in it?
It is fairly easy to circular breathe.
To practice without a didge first, make a tight embouchre, like a fishes date, and breathe out. Your cheeks will puff up. Push the air out through your pursed mouth using both cheeks and lungs to provide pressure. Remember the air will only be leaking out slowly since your lips will be pursed tightly.
Now, take quick snatches of air through your nose as your cheeks maintain the slow flow of air out though your pursed lips. This way you can continually top up your lungs with fresh air while maintaining the constant stream of slow, pressurised air. When playing the didge you are not blowing much air out through your mouth, despite the width of the didge, as it is choked back by your lips.
Keep practicing this and make the snatches of air larger and larger until you are circular breathing. Then practice on a cardboard tube by circular breathing a raspberry into the tube until you get a resonance.
Easy peasy.
If you want to buy a good didge get one that is flared out a bit at the end, has a nice resonance and look that it is formed by termites, not drilled out. But a cardboard tube works well - and you can get the kids to paint it.
The Swiss and Tibetans have their own didge: alphorns. They just have to learn circular breathing 
They have no holes, but has anybody thought of making holes in them so they can be played like a giant flute ?
I think the different notes are made by the voice of the didge player – you really are kind of humming into the thing. It’s almost like a giant kazoo, methinks. I am getting better with my circular breathing, but not great. Practice, practice, practice.
Ok, here’s my attempt at a homemade didge, along with my first attempt to play it.
There is no real mouthpiece yet, I need to either get some beeswax or some Plastidip (I think painting the thing black and using bright red plastidip would look awesome).
It seems that 8 years of tuba playing has helped with the embochure and the circular breathing. Although I gotta say that I can see how it will help with the apnea, my throat and soft palate is pretty sore right now.
Good times… yeah…
Apologies to actual Aussies.