Don't know how late in the year you can catch kokanee, I think I read somewhere that the adults go spawn in streams in the fall.

Have you tried a Double whammy kokanee pro (2 hook green and red wedding ring) to catch them? We had good luck on American, Chelan, Lake Kachess and Alder with it rigged after a Ford Fender and tipped with a worm, chartruse(spelling?) power bait or a little of both.

I've mostly fished for them in the spring around memorial day so I'll really be interested to hear if you have any luck at this time of year. Though any day fishing is better than working whether you catch them or not!