If I wore a "femme" necklace in my city, two things would happen...
1) I'd get too many nosey sorts asking what it meant, and it's not really something I'm keen to discuss with those not in the know;
2) Even if a butch saw it, they're not looking for femmes!
I'm present in my local community, and I've been present and active for many years. I know many people, and people do know... unless they're younger, just out or visiting, and then they think I'm the straight girl at the gay bar!
As for visibility... I struggle with how to do it, or whether I really want it. Saskatoon is a pretty decent place, where if people don't approve of queerness, at least (among adults) they don't waste their breath or energy trying to hurt you.
Besides... whenever I see a cute butch, I just give 'em the old eye-sex treatment. You know the one. Sultry eye contact, break away, see if they're still looking, telepathically communicate the desire for a drink and conversation, etc. When it works, it works!