The only two problems with water in maggies: One is that water doesn't work very well if the brake is dragged for long periods and heats up, e.g. if your doing downhilling. It will become spongy. The other problem with it is the viscosity (thickness of the water) is less than blood oil. I found under really hard pulling of the brake it seeps out, the solution is to use steel beed cables like goodridge. but far the cheepest and most effective answer for trials riders who want quick maggies with a solid feel.