I do, and here's how I do it. I take the old potting soil, put it in a 3 gallon pot, and pour a kettle of boiling water through to kill it, then I mix it half and half with new potting soil. Things grow very well in this, and I've never had any root rot problems from the old soil.
Didymo (Didymosphenia geminata), also known as rock snot, is a non-native invasive microscopic algae (diatom) that can produce large amounts of stalk material to form thick brown mats on stream bottoms.
Aboriginal peoples of northern Australia developed this strange wind instrument over 1,500 years ago. Called by many names by various tribes, and still in use to this day, the didgeridoo is a long, wooden, pipe-like horn created by hollowing out a dead wooden limb and coated on one end with wax.