White Flute + Black Flute

Here's an interesting topic. If you use the white/black flute and fight a wild pokemon, then kill it or run away, will the flutes effects wear off? If yes, does this mean that to use them properly, you have to use them after each battle, entering a house, and when changing an area?

another cool thing. what is the maximum wild pokemon attraction/repeling combo that you can think off? This is my combo:

Attract:
1- White Flute + Sweet Scent
2- Volbeat (illuminate trait) + White Flute

Repel:
1- Max Repel (duh)
2- Muk (stench trait) + Black Flute

oh, and also, will any of the attracting combos increase the possibilities of encountering a shiny poke? i hope it does, cause i still have not caught any shinies...