just water......
hummm in fact i should have taken a pic of a house i did 6 months ago....nasty place....6 mths later...still pretty clean, less of course spills etc....but no resoil issues....
water water...and for now its not soft....
know of a few others who just use water to....goood stuff....
mix between 1-4 oz a GALLON....depending on soil...i usually am at 20 oz in a hydro force...no tip 7 qt jug....