I think I read somewhere that just plain vitamin c at bedtime will help, I think emergen c was recommended.
I cut carbs out of my pwo shakes for awhile, and have been using thib's low carb post workout carbless shake w/ glutamine and glycine for a week. Its in his refined physique transformation article.
Normally, I'll be down about 2-3 lbs after a week of low carbs, that comes back on w/ my carb ups. Mostly water weight from the glycogen. I haven't noticed it this week. I don't know what effect it has on cortisol, but it is an interesting observation.
I'm going to play with the dosage a little bit and see if the effect continues, and may even cut my carb ups to every 2 weeks if it does.