The Chippex system is expensive touch up paint. The point of the lipstick, must be the waterproof variety, is that it can be rubbed into the scratch, then cleaned off the surrounding area leaving only the scratch filled. (Several layers) If the same could be done with touch up paint it would be fine but even with an 000 artists brush it never seems to just fill the scratch, it overlaps and looks unsightly especially when lacquer is applied, the aim is to make sure that your eye is not drawn to ugly touch up paint lines.
Regards Geoff Peace.