There are 2 reasons why I would not recommend using ww fluid:
1. The concentration of methanol can be inconsistent
2. Depending where you live it may be difficult to find -40 degree fluid (which is what you're looking for because it has a higher concentration of methanol
3. They coloring they use can build up and clog your nozzle.
As far as real life experience with these problems, I honestly have none. These were the things I was told, and I simply stayed away just in case.
And longshot is right, you absolutely NEED a tune.