You really need to knock off with the disinformation!
Yes, UV will ABSOLUTELY kill ICK.
ICK cannot cyst into a dormant state forever in your gravel, in a wet/warm/safe environment the ICK life cycle does NOT "freeze in place" or go into suspended animation. It will eventually have to go to the free swimming stage to infect/attach to your fish. If it fails to do so, it will die from lack of food/nutrition. Logic will simply provide you with the truth here, well, logic and having taken Biology 101.
You must run the UV, CONSTANTLY, though AT LEAST one whole/complete lifecycle of the ICK to kill/remove it, minimum. Personally, I would exceed that time period by a factor of two--just for my own piece of mind. And, in reality, I run UV on ALL my tanks 24/7. I have not seen a case of ICK since doing so.
Now, all that said, it IS possible for the ICK to go into some suspended state somewhere, in the tank, possibly. Such as above the water line in a relative dry environment, in a crack in such a place, etc. So, it is quite possible the ICK may return at some later date. IF THERE IS NO UV RUNNING. If it does, guess what, turn the UV back on, duh!
If you doubt me, there is a relatively easy test, to test and find the truth for yourself--simply run the UV 24/7 for a month. See if there is any ICK on your fish after just a few days--end of story ...
Regards,
JS