If you want to get it done right, I would recommend leaving that to the professionals & contact a spa/etc in your area that provides a relaxing & quiet environment to make you feel comfortable.
If you opt for the other options, I've HEARD powder works a helluva lot better than the pills & TOO many pills can cause a reverse affect (i.e. popping laxatives).
hehe, I assume one will be able to get a better seal with the rectum using a garden hose as opposed to a large shower head with massaging bumps on it... OUCH!
"They" (medical professionals) reccomend having it done 3-4 times I believe too. For monetary gain? Who knows... but i've heard about people going in first time... nasty black stuff comes out and then each time there after it's less "nasty" and "normal" ... so one must be penetrated a few times for it to clean you out
I think I'd opt for a really strict vegetarian diet first and loads of fiber to really clean ya out.