Steel wool scrubs away what is stubborn, so it is read as harsh effort to remove an old mark or habit. Dream books also link it to being too rough on yourself.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.