Colon cleansing before a long Water Fast.

I think the consensus here is that the Colon shouldn't be cleaned (except naturally) during a long Water Fast. That means it should be cleaned before. Now the question is 'How do you clean your Colon?'. I'd like to get some replies this time. I've been feeling ignored at this Water Fasting only Forum.
The 'secret of Life' is in the Colon.....if healthy and strong, it Shows. If clogged and sluggish the Body grinds to a halt.
So let's clean our colons. Someone tell me How??? I'm not into Enemas or Colonics, so could you suggest another way? If left to my own devises I'm going to use Oxypowder and Grapefruit Juice. My Grapefruit tree is loaded with ripe fruit, and I have 2 bottles of Oxypowder .
Now, once our colons are clean, we may begin our long Water Fasts. I think an amazing thing will happen. But, it will be different for all of us......WY