The tips can usually be cleaned with a good metal polish (ie
P21S Finish Restorer). Just wipe it on with medium pressure and a soft cloth and it should have an incredible shine. I use the metal polish to spot treat areas on my wheels and trim. We have an article on taking care of them as well here
http://www.detailedimage.com/Ask-a-P...tip-detailing/!
Greg @ DI