I have those tips (these are the tips used on the GP GTX package) on my GTP. I've been contemplating getting those on my SSEi and flipping them over. I think it would look great as well.
As for keeping them clean, here'* what I did before I installed them on my GTP:
1. I taped/masked off the outside/outside lip and then sprayed the inside with a couple coats of high-temp engine paint (black) followed with a couple coats of High-Temp Clear. Let it dry.
2. Cleaned the outside with AutoPrep (wearing rubber gloves to keep off finger prints/grease off
) Let dry.
3. Hit the chrome surfaces with some Eastwood DiamondCoat clear (http://www.eastwoodco.com/shopping/p...ond+coat+clear
4. After a couple of days of letting the Diamond Coat cure, I applied a couple coats of Liquid Glass. (I'm sure any wax would work too.)
When I wash the car, I just wipe them clean.