Use heavy cream, or whipping cream, as that is what you are supposed to be using on the WOE...and I guess how much to use is up to you...depends on how much cream ration you have left over...and how many carbs you want to use up. I usually use a couple of tablespoons anyway...it truly is good.
This also works with other flavored drinks...like diet wild cherry, diet chocolate drinks...not sure if you can get that any more..etc.
Have fun..it is delicious