There are are few threads in the past here too, if you "search" for them.
One I picked up that I ended up modifying slightly: 4:1 water:isopropyl alcohol. Except that I used 8:1, to cut down the aggressiveness of the alcohol. Worked really well.
Suppose to use distilled water, but I can get low particulate de-ionized water where I work, so I used that.