Obviously, you're much cooler than us. I bet if you take your awesomely, superior Netherland flares out for a couple of years of cat sailing, then leave them in the bottom of your catbox rolling around for a couple more years, you'd see the same results.
Actually when I worked as a cat sailing instructur for several years I made a bet with the sailing school owner to that extent. He bet that the most old and worn down flares that we could find would still show a 100% succes rate. We found some at the bottom of some locker that were covered in thick brown rust all over and were 4 years over date (meaning over 7 years old at least); these had been carried unprotected in lifevest for several years. We tested them all and I lost this best, they all fired and burned like new.
Since then I've tested all my old flares; often forgetting some of them thus having them several year past their dates. And what do you know I still have a 100% succes rate.
These babies are the cheapest available and have proven to be utterly dependable. Maybe you should buy a crate of these.
Wouter