Hi there ogr... due to the odd occasion to have had a girlie passenger not wearing sensible boots/shoes I have used an old penny to gently scrape off the plastic as it is softer than the chrome surface then a quick polish...dont use a newish copper coin as they have a high nickle iron content....easiest way to check the penny is with a magnet if it sticks dont use it.....hope this helps.......
Depending on how big the blob of plastic is
I've used the following method
As I've had to remove the melted remains of a ladies boot heel from a silencer before
Heating up the plastic with a heat gun or hair drier & slicing off as much as possible, is a good start
For the residue, wait till it's hardened again, then adopt the suggestions above
A fine "suede" or brass wire brush (softer than the chrome) will get the last bits off
I find it's best to do this when the exhaust is hot *
Final polish with Solvol or chrome cleaner of your choice & job done
* Chrome is a very hard but quite porous metal.
Minute particles of plastic will be embedded into the surface.
Getting the silencer hot will expand the surface and mke it easier to dislodge any remaining deposits
Ahhh John... as you know Duct/Gaffa tape is my bestest friend.. seeing as Ziggy is held together with it.. I may as well colour co-ordinate my textiles too