Speaking of pneumatic tools: I use the ball chisel grinder attachment but only for my butthole.
Kutzall Extreme Ball Rotary Burr 1/4 Inch Shaft Very Coarse Woodworking Attachment For Bosch Dewalt Milwaukee Makita Tools Abrasive Carbide 1" (25.4 mm) Head Diameter Sx-1C https://www.amazon.de/dp/B071X5BL3D/ref=cm_sw_r_apan_i_ZDV0FWZH6YB262VEJ3MH?_encoding=UTF8&psc=1