My wife (who rides her own bike, but occasionally still likes to go "two up"...) has a really bad habit of resting her boot heels on my pipes, as does my youngest son. A set of leather work gloves, a bucket of warm water, an SOS pad, and some elbow grease sort it out every time. I have come to expect it each time they ride with me, so I just wait 10 - 15 minutes for the pipes to cool down a bit, and scrub the rubber off. One time my son practically melted the sole off of his boot (I thought my belt drive was breaking down, it smelled so bad!), and it came off with a little effort. No scratches, and no worries about buggering up your paint job with over cleaner. Just another idea. I've been cleaning my pipes (actually all my chrome) for years, and have never had any regrets.

 

wont an sos pad scratch it all up? is there a certain grit you use?

 

I use very fine steel wool to remove crud from the pipes. Don't try to rub a hole in it, just use light to medium pressure and it takes the burned on stuff right off. Sometimes I use a bit of chrome paste with the steel wool. No scratches to date. And I've found nothing better. I'm done with the solvents.
Good luck!