No grinder. You want one of these with a nylon wheel like this. It removes dirt and bark quick as shit and doesn't damage the underlying wood.
Handheld 1400W Metal Burnishing Machine,Electric Sander Polisher for Wood Stainless Steel Polishing with One Wheel,6 Variable Speed,Lock Switch,Auxiliary Handle https://www.amazon.com/dp/B08G8BZC7V/ref=cm_sw_r_apan_glt_i_HW47X9B6FFBHDAJ8ZE0J