cleaning edges of reclaimed floorboards

I have a wood floor question. I recently bought maple floorboards from a torn-down gym. I have managed to separate them all and grind all the nails. Now I need to clean the tongue and groove edges where there is old finish and other gunk. What is the best way? Hand scrape with a flat piece of metal? Use a router to redo the edges? Or???
Erik
Replies
The router will work for the grooves, but the nail stubs in the tongue side will snag the bit.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I reuses some oak flooring. Monuted a electric motor with a wire wheel and ran all edges of the board down the wheel. Some of the lond boards it took 2 guys to handle.