Some double reeds are a bogger to keep in tune.

A single reed call goes "quack". Double reed: "Quack, quack". Sorry, couldn't resist.

Alabama, I use my dad's old Olt call too. When I was a kid the reed fell out. He sent it back to them, they replaced it, but it fell out again the next time we went out. Kinda broke his heart. He put it back in the little box they sent it in and I found it in his drawer after he died ten years ago. I did some research and found that the company had gone under a few years earlier. However, a couple of the factory hands started up their own business remanufacturing them. They sent me a couple of reeds and new corks. It works good as new now. Dad would be tickled. Sadly, the old lanyard he braided when he was a kid was too fragile so I put it away. Braided my own from some camo decoy cord I ordered on line. I'm sure it will last another generation. Hopefully hunting will too.

http://duckcallsgoosecalls.com/
The outer "reed" is not a sound-producing device, but a return spring. It allows you to blow harder and the reed strikes the tone board harder. Thus, it gets more range. True, they require re-tuning for every outing, but this should be unchallenging. Plastic reed materials have memory, and need to be precisely re-bent for proper action.