Actually I must say I've now seen some results of what can be achieved if it's done correctly and I'm really surprised.
The method is fill scratch until over the level of the surrounding paint work with paint. Wet sand with Unigrit 2500 and or 3000 grit until completely flush and then use a random orbit polisher to get the shine back in the paintwork. Seal and Wax. Job done.
See this post over on detailingworld. Amazing stuff.
http://www.detailingworld.com/showth...light=wet+sand