Chad...don't be disheartened, we've got the answers for you, so hang on;) One explanation is that on the forum where this was posted it doesn't have the high visibility that the other areas do, sorry about that, but I'm glad that you asked the question.
I too have an ODD student in my class, so here are some thoughts...
Our theory of WBT is that you need to first get the strong 80% of your kids on your side. You do this by using the scoreboard and the teach/okay and so on...the things in the "1st Steps" menu up on top of this page. These are things that you have probably already started so keep those thing up.
Now, what to do with your ODD student? I was new to the whole ODD aspect this year also so I had to do some research to see how this would work with WBT and what did the whole ODD diagnosis mean. When I talked with my school psychologist she told me that WBT is good for him, but you will need to be
patient. You see, when he starts to shut down, nothing will break through this persona. I at first thought it was just a bad attitude and "he wasn't going to do this to me!

" Well I learned that I need to be more patient with him. You are going to have to have a sit down meeting with your class and tell them that
Johnnie is acting different because that is just the way he was made. He needs our help, patience, and understanding. The thing that I told them was that we will treat him normal, but don't you dare think that you can try this stuff!

This really helped.
Now, fast forward to today, 7 months later...He participates when he wants to and he does a good job when he does participate. I have found a partner that he can work with well, but it is almost a reward, because if they start goofing off then they need to do it with another partner. Is it a perfect system? No, but I am getting more from him than he gave me in the beginning.
He is a candidate for the practice card system as long as you explain it to him well first and he understands that it is a practice time, not a punishment. You see, kids are coming to your class familiar with the system of school and that you are going to
punish them if they mess up. In our system, they are not punished, they just get some extra practice...one minute by the way. So as long as they know that it's not punishment, it can be swallowed a little easier. Of course you tell them all of this with a smile.
I hope this will help as you start next week. Go for it with all that you have. He may surprise you and see everyone and jump right in. I have found many times, it's all how I "pitch" it to him and the class. Since everyone will be totally into it already, he may not have any support from the other kids if he gets negative. Keep us posted...
Power to the Teacher!
Chris Rekstad