I used to run it on one of my first Subaru's, experimented loads with it and give up with it in the end.
I used an Aquamist 1s system running water at first then 70% water 30% methanol them 50/50 then 30% water 70% methanol then 100% methanol
It was pretty good at det suppression in all guises but the 1s system is pretty crude using a boost pressure activated delivery system, I ended up using a quite small jet 0.3mm as any more would induce a misfire with any more than 50% water.
I gave up as the system I was using didn't cut it and I felt it wasn't worth investing in the better system for the gains it produced when compared to adding methanol to the fuel.
In the end I ran 10% methanol in the fuel, this gave reliable results, if you look at going down the methanol in the fuel route make sure you over size your injector spec as you will need to add a little more fuel to get the AFR's right, this is because methanol is oxygenated.
You can get methanol here-
www.jennychem.co.ukand Aquamist system-
http://www.aquamist.co.uk/vbulletin/index.php?s=c77f1769439137751b88ae32e0bd2e18Hope this answers a few questions.