Melted boot soles or wax can be a pain to remove from your exhaust pipes. Cleaners are to rich for my blood. I found if you spray a little "Brake Cleaner" on a rough cloth, with little rubbing the marks come right off. Just make sure the exhaust is cool.

 

EZ Off oven cleaned works great on chrome for me. Don't let it sit too long.

 

Brass wool won't scratch

 

Nevr-Dul works for me.

 

I use 0000 steel wool on chrome.