Yeah that Meguiar's product is a total waste of money. Don't know on the Dupli-color option, but it seems like it was discussed in the Line-X thread. Do a search for it, I think there was a conversation between one of our members and a Line-X rep regarding other do-it-yourself products like Dupli-color, Herculiner, etc.
If I find it first I'll post it.
PLEASE also remember that if you try the Meguiar's product to be EXTREMELY careful not to get any on the paint. It WILL discolor your paint ... PERMANENTLY.