I don't hose the dirt out, but do shake out what I can so that they get new, loose soil to help them grow. It isn't all that easy to do for someone my age, so I just do the best I can. You won't hurt your brug if you leave some of the old soil attached. If you have a fungicide (powdered) it wouldn't hurt to dip the cut ends of the roots into it to prevent disease.
Room 4 1 more?
violabird,I lay the pot on its side and hose out about half the dirt.Replace with compost and water in well.Works for me and saves the back.Throw the old dirt on the garden.