Even after you attach the destiny knot to the ditto though, getting all 6 IVs perfect is going to be up to luck. Do you know how many perfect IVs your Houndour has? The ideal setup for getting your perfect timid shiny Houndour is this:
6IV Houndour(Everstone + timid) + 6IV Ditto(Japanese + Destiny Knot)
Then it's just a matter of breeding until you get a shiny. The resulting shiny will have guaranteed 5 perfect IVs, but not necessarily 6. There is no way to GUARANTEE 6 perfect IVs through breeding.
My advice, once you find a shiny with 5IVs, i'd call it good. :)