That's exactly what my mother used to do, heavier strings, also took her guitar (a smallish late 1940s Martin) in to be set up for it. "It" was 3 semitones down from regular, so the E strings were down to C#. Worked well on that guitar, which didn't have the best high end. I don't know what they did, probably something with the nut but I didn't ask. She's long gone as is the guitar (too small for my hands) so I can't ask or look.