I would actually do a Bowel Cleanse first, before a parasite cleanse. It helps get some of the hiding places out of you, and may actually clear some parasites.
I liked Oxypowder , personally. Did I see ropes coming out of me? No. Did I get rid of mucoid plaque? Not sure. Did I feel "cleaner" after the 7 days? Heck yes. Plus it will help with your constipation.
If you're somewhat constipated, I would NOT recommend doing P&B shakes. They can constipate some people and if you need to loosen things up, they could be a bad thing.
By the way, did you know that a Master Cleanse is a type of a kidney flush? So you've already checked one off your list!
Also, you can go ahead and do a Liver Flush if you've been off the Master-Cleanse long enough to start eating what you would consider to be your regular diet.