I haven't hunted it since Rita but we ran in the canals with the big motor, push pole or trolling motor into the ponds, cover boat with burlap, and hunt in the grass nearby. You can walk most of the area but I wouldn't want to go far. Most of it is shallow but the mud will keep you from getting too motivated. Especially without knowing where you are going ahead of time. There is a separate walk-in/ paddle area but I've never tried it. If I were you I would try to find a good trolling motor and throw it in the back of the truck along with your boat, take paddles/ pushpoles in case the trolling motor craps out, GPS a couple spots using google earth so you have options, and get out there early.
When we used to hunt it 90% of the people would stop within 500 yards of a canal so pushing further in can be rewarding.
Your decoys are fine.http://www.fws.gov/southeast/pubs/SWLcomplex_hunt.pdf