In my very humble opinion, this is a "bad thing".
1. Rags disintegrate - a loose thread wrapping itself around the compressor is unlikely to improve performance
2. Any debris or minor dirt that gets caught in the rag is pretty tricky to spot and even more difficult to keep hold of as you remove the rag.
Instead, this is what I've done:
It's a welding pipe stopper, the 70-87mm size is a perfect fit and it's a tidy install so you can make sure everything is spotless before pulling it out and replacing the airbox.
A tip-top top tip. Thank you.
