Not to long ago I posted a thread about my T-4 being too loud (it went WAY off track, and kind of my own fault). Well an HD buddy of mine suggested that I use a steel scrubbing pad instead of fiberglass. He said to get the kind with the heavier strands and not steel wool or anything with detergent in it. He said that it won't break down and blow glass fiber all over my bike. But will quiet my pipes plenty. He normally rolls open pipe but uses that to square the occasional fix it ticket. I may have to give that a go and see how it works.