I walked a thousand steps through filthy ash to get Black Flute which is supposed to repel wild Pokémon. This is what it says:
A glass flute that keeps away wild POKéMON.
And the White one:
A glass flute that lures wild POKéMON.
I've read Bulbapedia on the topic, but I'm not satisfied - it doesn't say how long the effect lasts.
I can't see any effect after using any of these. How long do they last?