Peter,
use longer hooklinks than usual, and if you can use a helicoptor rig, this will stop your rig getting dragged down into all the stinky stuff and ruining your presentation. Pop ups are good over silt as you can present a bait just above the chod.
Best to use lighter leads as well, stops your lead from plunging straight into teh silt especially if your giving it the "hail mary" from the bank!!