Allow me to elaborate.
The idea is a good one. It just seems to be poorly executed in the photos shown. First of all, it's a mix of steel and aluminum. No big deal. However, the threaded portion appears to be 1/4". I wouldn't trust that thing to hold tension, as well as up to 9k rpm and all the vibration in that area, especially considering that belt runs the WP, Alt. and PS by proxy. Believe it or not, that belt sees a lot of load and vibration. Even the JayRacing turnbuckle is built of larger than 1/4" stock. 3/8" would probably be acceptable. That seems to be close to what the Jayracing kit utilizes.
Additionally, OP is posting photos presumably from under the hood of their car, and one can clearly see a FERNCO (aka home depot) rubber (not silicone) coupler on the hotside IC pipe. Thus the OMGWTFGTFOWITHTHATSHITWTFDOYOUTHINKYOU'REDOING portion of my previous post.
I don't mean to hurt anybody's feel-bads.. but Damn.