During the crazy cargo days, we were using TKS fluid to deice. During the light icing condition, it worked pretty well, but I hate to say that anything more than moderate icing conditions, the TKS will lose it’s effectiveness. Like OSY007 said, stay out of the icing condition as long as possible. Usually other pilot report is a great source to avoid icing. If you really need to descent for the airport or the approach, then make a steep descent, penetrate the icing lair as quick as possible.