I myself am not in favour of using Oxypowder for a cleanse. I am not convinced it is not habit forming, and that it actually liquifies your mucoid plaque.
The experience that I have had recently has been quite challenging. I recently started a candida diet and BP Shake colon cleanse, but I have had difficulty with keeping my fibre intake up, so I have had difficulties with constipation. You must alway keep constipation in mind while doing any of this. It must be avoided or dealt with before you deal with anything else.
I would suggest that you make sure to find a whole grain (not brown rice to start with) like buckwheat, quinoa, rolled oats that you can eat every day to keep you regular and start off with taking just psyllium shakes (no bentonite- it can constipate you worse) to get your bowels in a good regular mode. Once you are having good regular BMs, you can start adding the Bentonite to your shakes. You can start your parasite cleanse shortly after you start adding the bentonite. I don't know what parasite cleanse you have ordered, but there are some (like Clarkia ) that apparently kill candida too.
Don't freak out if you get constipated initially- if you have candida, it tends to cause constipation, psyllium also constipates initially. Just keep taking the psyllium shakes as outlined in PTree's posting- she is an expert- trust her. Not everybody takes well to psyllium though, so if you get severe gas or bloating- there are other options out there for you.
What can also help is if you take 1 tsp of olive oil or flax-seed oil 3 times a day. If you desperately need to void your bowels take three whole garlic cloves at night, then drink very warm (but still drinkable) water as soon as you get up. Jump up and down or do some ab excercises, get regular excercise like walking or yoga to keep you regular. If you go to the Candida Forum Jhan has excellent posts on constipation- as does the 'Best of Shelly' link up top.
The most important thing you can do as you do these cleanses is to keep your bowel regular and clean. It will make your other cleanses that much more effective and comfortable. Just remember-slow and steady wins the race.