Have never tried drying the flowers, but a friend brought me a couple of branches with the pinkish-red pods which are very attractive. However, they became very brittle and shattered as I was rearranging them after a few months. I think they might have lasted longer if I'd left them alone. Although the pods had slowly turned brown, they were still attractive.

This tree is on my wishlist but I've never seen it for sale locally, though there are a few growing around town. Your question prompted me to look in several books but the only reference is for the flowers being used in fresh arrangements, just the pods being mentioned for drying.

Hope someone is growing it and will post with their experience. Unfortunately my pod-bearing friend has moved away, or I'd experiment myself with drying the flowers next summer. I'm always up for experimenting...josh

Here is a link that might be useful: Koelreuteria