I'm with Dave... a cerise jig tipped with a bit of prawn and you can just slay them. I put my jig direct to a swivel no leader. In six trips I've hooked close to 100 and only had one foul hooked. Most of those were taken with the bobber stop at ~2 feet. I can't picture how you would line a chum with a jig hanging straight down below a bobber.