They are double insulated and you would have to make your own wipers from phosphor-bronze. Be sure to make them long, if they are too short they don't act like a spring or could brake down the wheels. They have to cope with the wheel side play. You want to from them like a spoon to touch the inside of the wheel. You might want to use a tiny bit of Di-Electric Grease to enhance the pick-up.
I tried the ready to run Atlas caboose trucks with wipers installed and they just don't work properly so making my own is the alternative.