Cayenne is an irritant in the digestive system, but the gut tends to protect itself by producing mucus. This new mucus helps break up the older stuff. Cayenne promotes good circulation, kills parasites, can help breakdown waste and renew the bowel lining. It is good stuff, but as you've mentioned should not be used alone. Many people see mucus as the enemy, but it is a necessary part of a well functioning body when it is in proper balance. When cayenne allows new mucus to replace the older hardened stuff, it is doing the body a service. The key is to limit the amount of foods that result in mucus formation like animal products and allow the cayenne to do its work in the gut without affecting the whole body. Each individual will have to experiment to find their tolerance level, but the level will build over time and a person can safely use quite large amounts of cayenne without trouble.