I took this Grand Daddy Purple clone about 3 days ago:
It's at the bottom of my 2.5' x 2.5' tent so it doesn't get too much direct light. I dipped the cutting in Olivia's cloning gel and placed it straight into a soil less mix. I don't expect to see new growth for another 7-9 days on it. I'll put it up in the light when I see it start growing again.
I guess chucking them is a personal choice; if you absolutely want to keep it, I'd hold out until it was dry before I gave up. I'm doing that on a triploid GDP S2 plant I did; I'm trying to reveg it but there's only a few green spots left and the rest of the plant is smokeable it's so dry.
I've had clones that took weeks to start growing again, so I'd be patient as long as the cutting still looks green and alive.