such as aerosols away from the user it has been found that with the device of the embodiment of fig2 6 for example the side openings 43 and 45 are particularly effective to blow larger particles toward the bone and blow water away from the surgeon and that upper and lower openings 44 and 45 produce a coanda effect to blow small particles and aerosols as well as water away from the surgeon or other user it will also be noted that with particular reference to fig6 the angle of discharge of liquid from the blade along the narrow edges 30 31 of the blade will preferably be at an angle 34 a 34 of 30 u00b0 or less to provide a forward component of motion for liquid being discharged from the blade to facilitate driving the liquid toward the bone as aforesaid the air from openings such as the opening 43 45 likewise facilitates driving the liquid to the bone it will further be noted that if desired the water or other liquid channels 68 70 could be pressurized and or pulsed not shown to have air behind them to drive the water to the bone with greater force or in a pulsing manner and that such air being driven to the bone could be instead of or in addition to air provided via the.