Blue Ridge Beemers

I was cleaning and polishing on my R1200C tonight and came to the mufflers. Well... They need to have the melted rubber cleaned off from where my heel touches them and I was wondering what the most popular method was. Mine of course are chrome and most of the mess is simply rubber of some sort. I think mostly from a pair of Dr. Martens I had on.
Any suggestions? Right now I soaked them in penetrating oil hoping to soften the stuff, then I thought bug and tar remover?
Thanks