I did a bit of quick research on root zone temps for plants just now. The optimum range for most plants is 68-72, a good safe range has been shown to be 65-75. Temperatures above 80 result in noticeable things such as wilting, flower drop, and fruit damage. While salt causes minor damage at low concentrations I think it is a safer alternative to high temperatures. I appreciate the suggestion however and it's good to get this information out there for others to see.
Understood, good to know.