I use a minimal amount of conditioning year round. This is for my English Lops, and since I have trouble keeping weight on my guys, you may want to cut back on the amounts for your buns.
I feed black oil sunflower seeds [hearts and shells], about 1 seed per lb of bunny every other day. If a rabbit is in a molt, then I feed extra to get them out of it faster. Thus, you need to be careful not to overfeed these, as they'll make the bunny blow its coat. They also cause weight gain.
I've recently started giving a small amount of wheat germ oil every few days. The results have been fantastic- Nice smooth coat, and better flesh condition.
I feed about two pinches of old fashioned rolled oats every couple of days to help keep weight on the buns. They looove it.
I have fed Calf Manna in the past for underweight buns, but I wasn't too pleased with the results. It was good for getting weight back on my rabbits when they picked up worms from a show, but I like the results from the wheat germ oil much better.
I've found that fresh herbs cause the coats to be soft and smooth. When possible, I grow my own herbs, including parsley, oregano, basil, mint, marjoram, rosemary, and sage. Since increasing the amount of herbs my buns get daily, I've gotten better comments on coat type, and I've been able to cut back on my conditioning formula.
If the show is in two weeks, I wouldn't stress too much about it. Maybe a black oil sunflower seed or two would help, or possible some herbs, but overfeeding any conditioning this soon will just cause her [him?] to blow her coat.
I've never heard of using oranges for their coats... What effects exactly do they have?
Holly