I am also experimenting with faecal incontinence, wearing hollow butt plug. It works, but is very uncomfortable and also a feel of uncontrollable pooping is dismissed.
There is another method commonly used for treating anal fissures. This method is based on temporal relaxing of anal shincter by botulinum toxin injection (mainly used in cosmetic). The injection is without pain and relax your muscle for about 3-5 month. Depending on dosage can lead to total temporal incontinence. After this interval the muscle activity will return.
Injection without proper diagnose is not officially approved, so it will be hard fo find physician for doing this.