Ron,

I hesitate to jump in here because this is a grey area for me, but I decided to take the plunge, with a prayer.

This is an opportunity to try a little different type of 'educating'. Find the tightest pants you own, (preferably not your favourites) and slit them up the outside of the leg so that you can put on your brace after you put the pants on. Fasten the pant leg somehow so that it doesn't flap. Make them as presentable as you can. Then wear them to work.

You haven't broken the rules, you are wearing pants. When you run out of pants, tell your boss that you have run out of pants that you can wear with your brace.
Since:
1) you are being environmentally conscious and only washing full loads, not half loads, of laundry,
2) you don't have any more pants which you can afford to cut up, and
3) you don't have the budget to buy more pants which will never be used again when you are done with the brace.
Ask if could you wear your kilt while laundry is being done.

Now, your kilts will look better than the pants. Perhaps he will see that, at least we can hope...not a permanent solution, but a baby-step.