Oldlibs has other things in it, so doing # aptitude purge ~i~soldlibs will zap more than just transitional / dummy packages. (However few of them are there in the first place.)
Also crossing ones fingers and hunting for strings is an inexact method. What if a description has "this is a package for the transitional music scale" or "this is a package for people who think they are a dummy." etc. This is like some country's border guard looking at people's hair color because passport haven't been invented yet.
