Totally sounds like die off to me. This is interesting to me because I plan to do a Bowel Cleanse with Colosan (very similar) and I didn't even think that I would get die off. I guess I should expect that.
I tend to get the exact same symptoms you do anytime I do a parasite cleanse, or even if I eat fresh pumpkin seeds. The flu-like, achy all over thing is the sign for me.