I get much more life out of my abrasives and a quicker cut by floating the metal residue with some kind of fluid. I started out, like everybody else, with Wd-40, but hated the black staining ink mess it made, and being a lubricant it only sort of aids in the cut. I quickly got away from oil based fluids for all of these reason's. My very good friend Dr. Lucie showed me how well formula 409 cleaner worked, as does simple green, but I am not fond of the latter. These water based fluids, rather than lubricate, help the abrasive cut more effectively and clean up very nicely. The trick with water based fluids is to defeat the rusting that can occur, this can be done with detergents or by shifting the pH up to the base side, which is why Windex and other ammonia based cleaners will work.
I eventually started mixing my own- water, a couple drops of Dawn (for a surfactant), a little ammonia, perhaps some TSP (very good cleanup) and then cut is with a decent amount of denatured alcohol. The alcohol helps dry the blade off with time even if the higher pH stops the rust. I used this for some time, and still do in a pinch, but one day I realized that I had gallons of actual fluid designed to prevent rust while aiding in cutting operations in the form of my water based coolants in my diamond saw, surface grinder and mills. Now I just fill a spray bottle up with the same cutting fluid and go at it, but I may add little of my old ingredients to help with certain applications.