I have seen a number of trout stomachs over the years that had one or more pieces of soft plastics in their stomachs. In nearly every case those plastic grubs, worms, etc. were scented. As such under WDFW definition such "lures" would be considered to be bait and therefore not legal in any selective fishery where anglers are required to release fish.

From WDFW regulation definitions
"Bait. Any substance which attracts fish by scent or flavors,..."

Curt