You should do that twice a year. The motor brush's corrode from sitting and the solenoid contacts can also corrode. That's the number one failure on a winch. If it does happen, you now need to tear it down to clean them. Way easier to run it in and out occasionally.
I haven't seen a brushless motor on a winch yet but someone runs a solid state control instead of a solenoid. (warn still runs solenoids).
