To assure that no organic residue is left especially after a coffee enema, after you rinse your enema bag to your liking put some baking soda in a few teaspoons will do, add enough water to shake around and coat the bag run some through the tubing and rinse lightly. This will leave a thin alkaline residue and will inhibit most bacteria. Allow the bag and tubing to air dry thoroughly. Rinse again before using.
In addition enema bags should always be cleaned somewhat thouroughly after use as back flow can occur into the bag in certain circumstances.
I remember a while back I saw a post where someone had discovered thick black mold in the enema bag and no one responded to them and they never posted back. Hopefully things worked out ok. I always look inside now I need to look in the hose!!!