I thought about doing this with mine as well since I run large scale waterjets at work but got rid of the idea when I really thought about it. You’d be spending a fortune on abrasive alone as something this small would realistically use a similar amount per minute compared to a full scale waterjet, but you’d be cutting much slower.
You’d also need some sort of way to enable/disable the water flow via PWM/Gcode or whatever. It’s technically possible to do it manually but it’d be a pain in the ass to program as you’d need a long dwell time to shut off the abrasive, then the water before moving on to the next cut/finishing. This could be done with something like a tool change in a gcode file.
None of that was worth it to me so I just ditched the idea.