for a start, if you search for washerwoman in the DT, you'll get some hits, but that's only the beginning: scroll down to where it says play.exe IRISHWSH. The stuff in caps is the name of the tunefile. Now try a search for *IRISHWSH (there's really an unprintable character between the play.exe part and the tune filename, and the wildcard takes care of the whole thing) and you'll get nine sets of lyrics that work.

There';s a lot more to DigiTrad than searching for titles.