I use Oxypowder as well. It is amazing, but you have to use it right to get the best results. Even if you don't, it will still work. In other words, if you take it at night you will be going the next morning. If not immediately, as soon as you drink some water you WILL be going.
I suggest using Para-Buster or something similar as well. You will pass parasites on Oxypowder , but only some of the ones in your digestive tract. It won't kill the tough ones or the ones in places other than your intestines and colon.