As already stated, plastic is a poor conductor of heat. I would suspect that it will not work at all. I wonder what the 212 degree temperature entering the plastic tubing would do to it.
I use a 20ft coil of 3/8" copper in icewater and another as an IC. It works better that 40ft in the wort, but not by much.
It sounds like a modification of a plate chiller and would probably be more expensive to make and use. (if you have to buy ice)