Ryan,
Yes, there is toxic coating on some of the, and not knowing for certain, it's best to leave them alone. It will take more heat than a 'que to make the coating produce toxic fumes, but coals have the ability to melt steel with enough air, so the potential is there.
If you're looking to do this, go to the hardware store and get some small mild steel stock, if you get the really small stuff you should be able to bend it in a similar fashion.
Any type of zinc coating is toxic, this goes for nuts/bolts as well. You might not have worries about this, but there have been folks that have died, you can
read some about it here. Food for thought as they say, in this case I don't like the idea of anything toxic going near fire...but that's because I do forge...and I do know the dangers...all of our mileage varies...
The other point is that a rib rack costs about $10, and that could be wise money spent, IMO. Possibly stainless, not sure what they use, but I would have more comfort knowing there wasn't any zinc and/or lead myself...
I'm no expert on this subject, just try to keep things away from the coals, because I know that with a small hand blower you can melt steel with charcoal...
