???about oxy-powder use...(m)

I am starting my 3rd Master-Cleanse tomorrow. I know I am supposed to use the SWF, however, for my own reasons i will not be using it( cannot tolerate). I have some Oxypowder that i am going to use instead. For those who have used this, am I better taking this at bedtime or during the day. I am concerned if i use it during the day I will eliminate all the lemonaide I am taking in, which will include all nutrients from the drink. I have tried it at bedtime and found by middle of night I am up eliminating...any thoughts??
thanks!
Golden