Pat, reference what happens if you don't get out all the old anti or water. I'm not sure... They seem to recommend about a 3% mix is acceptable, I think thats around a 1/10th of a quart or so?
I THINK why they don't want WATER in with it is because your potentially running higher engine temps with lower pressure and the water WILL in that case turn to steam and be a problem. Long term, it may hinder the ability (degrade) the Evans. Mixing a little
antifreeze may prevent the steam pocket problem, but it will eventually degrade the Evans as well. Either way, it's a contaiminent within the cooling system.