In salmon rivers, it almost feels like you are cheating fishing eggs.
On the Bow River, I have caught whitefish on egg fly patterns.
Quite honestly, though, if I fish an egg, I use a trout beads and a toothpick with a dark hook dangling about 3-5 cm below the stoppered egg. It is more effective than any fly I have used. The separation between bead and hook means the hook set generally misses the small mouths of a whitefish, but trout hookups are unaffected and (so far) seems to avoid the risk of trout swallowing the hook.
Great looking flies btw.