There is a worm pattern using Brown Vermille,but it wasn't available back when I fished Rapjohn. Sounds like there are browns and Triploids in there now too,a more recent addition than when I fished there years ago.
Maybe worth a few more tries as triploids are a hungry breed and you could luck out on a Carey or Dragon with them. Maybe try a big leech at night too,for the Browns.
Yea,I love to chronomid whenever the hatch is on,which is all spring in the E.Wash. Lakes near where I live now. I even bloodworm frequently when the hatch is off and do fairly well at times.Getting old and lazy I guess.
As far as good lakes in So. King county you'll have to ask someone else as I wrote those lakes off as urban slews and fished only a few near Black Diamond.
In Pierce county Silver lake chronomids well as does Mineral near the pilings on the So. end when the hatch is strong. Bay Lake was a treat years ago, but is now ruined with millfoil and bass and algae/plankton so thick you can cut it.
I can only suggest that you spend a little more time/gas and get the heck out of So. King county and all Pierce county and fish
Thurston,Mason,and Lewis Cos.
As you get older you begin to understand that "fishing time" is a precious commodity and should not be wasted on water that has been ruined or is used exclusively to run a welfare meat program and has only 8-10" stockers.