I posted below with a link to the Ultimate Fast which combines MC, colon and parasite cleanses. There's no problem doing the simultaneously...just make sure that you take the parasite herbs (or any other herbs, supplements or medications) at least an hour before or after you take the p&b shakes.
This can be a pretty strenuous cleanse so It's probably a good idea to wait until after the holidays...especially if you are easily tempted by all the goodies!