You can, of course, brush them, however this will not last long. More radical means of plastic washer embedded between the half-loops.
There is another way to get rid of the squeak. You need to shorten rod one half loop and put the loop inside a steel bearing ball.
Recommend to read
THE INSTRUMENTAL IN THE FRIDGE
Not in a hurry to dump an old refrigerator (even if it was only on the door). He still will serve as a closet pantry and door stamped inner wall can be adapted for storage for tools....
BRAZING WITH PROPANE
Soldering metal tin solder — one of the most common but, unfortunately, the connection is not too strong. A more reliable seal provide so-called "hard" solders — silver-copper or...
