flats as sharps and sharp as flats

[Stefan Thomas]

Dear community,
I have a question about the great naturalize music function, I found at
http://lilypond.org/doc/v2.11/input/lsr/lilypond-snippets/Pitches#Pitches
Is it possible to define another function, that shows an written "dis"
as an "es" and vice versa?
I'm thinking of something like \showFlats { cis dis fis gis ais}
\showSharps { des es ges aes bes }.
I think, this could simplify the work with midi and rumor dramatically
and I guess, it should be not too difficult, to change the
naturalizeMusic function, for those, who have little experiences in
programming ( I don't have any).
Does someone have an idea, how this can be done?
Stefan