PLA basically doesn’t dissolve in any (readily available consumer-grade) solvents. Your best bet is going to be to take the entire unit as far apart as you can until it is metal only components, heat it with a heatgun to make the PLA soft/melt, and brush it all off with a brass cleaning brush.
What type of filament is that?
Maybe try a heatgun to soften it. I’m not sure, might damage the plastic casing.
PLA
PLA basically doesn’t dissolve in any (readily available consumer-grade) solvents. Your best bet is going to be to take the entire unit as far apart as you can until it is metal only components, heat it with a heatgun to make the PLA soft/melt, and brush it all off with a brass cleaning brush.