Helicopter rig, if this is what your referring to, can be used on all lake beds with all sorts of hookbaits. The chod rig is best used with a pop up. As has already been said you want to use a hooklink about 8-12 inches over a silty bottom. A short hooklink can result in the lead sinking into the silt and dragging the hooklink with it, either giving you a bad presentation or masking your hookpoint all together. Also may i ad try to use a supple hooklink material over silt, either normal braid, Korda supernatural gets my vote, or straight mono.
Cheers
Will