The first ritual was supposedly the swiftest, which involved the victim being thrown down a pit and having rocks thrown onto them. The rituals were increasingly slower and more painful, with the seventh being the slowest.
The Fourth Doctor, Romana and Rohm-Dutt were sentenced to die by the seventh holy ritual of the old book. This involved being tied with vines, known as creepers, that tightened under the sun. They would stretch the victim until the spinal column broke, causing death. When it rained, these creepers slackened and the trio escaped. (TV: The Power of Kroll)