Please do not use corn in any kokanee (or other trout) chum.
Some items that have been successfully used for kokanee chum include chicken mash, cottage cheese, oatmeal, crushed egg shells, and the old reiable "feed eggs" EAch of the old timers I fished with seemed to have their own secret chum recipes though one or more the above items were usually included.
The old school kokanee still fishing with a light fly rod rigged with mono, and egg sinker and hook(s) baited with periwinkles (caddis fly larvae) and a red egg is a blast and seems to be a forgot art. I have also used small pieces of raw prawn as a bait with great success (maggot size pieces of prawn is not a bad bait for trolling either).
BTW -
The fsihing regulations can always be found on line via WDFW's web site - just go to fishing and click on seasons and regulations.
Tight lines
Curt