if you wash the okra, let it dry, and then sautee it in a little olive or veggie oil, it doesn't get slimy. I love it too but I haven't tried to feed it to my birds. I just picked some up at the farmer's market so maybe when I cook it, I'll give them a nibble.
What about beans? I picked up fresh lima beans too, but I'm hesitant to give any to the birds. Don't want them gassy. Does anyone feed their birds any kinds of beans or lentils?