When I used bark, I used 1/2 pvc pipe about 10" long with caps on each end. The way I used them, there seldom was contact with the plant, but they can easily be made and easily sterilized in clorox as needed. This is not true for the old wooden potting sticks.
Now that I use CHC and coir more and more, just the finger pressure around the edge of the plant holds the cyms firmly.