Tabasco is allowed as per the Exante list of foods, see below. I much prefer Encona Hot Pepper sauce myself and I have a good squirt, probably about half a teaspoon in my soups. They make them much more palatable for me especially as I make the soups up with about 600-800ml boiling water to fill me up and add to my water intake. There isn't much flavour otherwise.
By the way, there is a warning about the new version of Coca Cola Zero on one of the pages here. It's better to have Dr Pepper Zero or some supermarket own brands.
http://www.exantediet.com/diet-plans/total-solution-list.list