Angg, I grew up in Renton and have never ever seen nets in the Cedar. I know in past years they would net the lake, but not the river itself.
As for your worm question, scent is scent and is illegal according to the regs. Try a bobber and jig set up for the big trout. It worked well for me the first day, but I haven't been back since. I'm recovering from knee surgery. I also hooked a few fish on a #3 all silver Blue fox spinner.
Good luck.