Question on colon cleansing

I'm kind of new on this site and posted this in another forum. Maybe I found the right forum to post this in.

I bought a used book titled Colon Health: the Key to a Vibrant Life, written by Norman Walker. I think the book was written in 1979. Anyway, the whole discussion in this book is about the importance of regular irrigating the colon. Included with the book is an illustrated drawing of a colon with a chart called the Colon Therapy Chart. The illustration shows where different parts of the body has a connection to the colon. He states colon irrigations are the first line of defense for any particular problem. If you have an ailment that is affecting that part of the body, he recommends doing a series of colon irrigations so the problem will correct itself. Then once you have cleaned the colon out, he recommends you do colon irrigations at least twice a year for life.

Would a good colon cleansing product do just as well as the colon irrigation? What product would be a good recommendation, and how often should this be done? Thanks so much for any feedback.