The rituals were very short. A team of false face members, wearing their masks and thus impersonating spirits, entered the longhouse, sealing the doors. No one could enter during the ritual, else the ritual was ruined and must be performed again. After a short dance, the false faces left, with the patient believing he had been cured. Since suggestion is such a powerful force and since the false faces frequently treated conditions such as depression or sadness, it would frequently work. The Iroquois also relied upon healers who used herbal remedies, some of which seem to have been beneficial. Willow bark was used to treat fevers, and contains the same substance found in aspirin. The healers also set broken bones skillfully and even performed minor surgery. They were probably at least as good as the European doctors of the era.