You can buy something like this to convert them back to the old nozzles. Sure, you're now at 3x the price of what the old cans cost in the first place, but it's worth it not too deal with the new nozzles.
I bought something like this kit and replaced the safety spout with it.
Mostly, you just need a vent hole on the can. A spout to replace the "no-spill" (yea right) spout is also helpful.
Here's one product on amazon that'll do the trick. This isn't a recommendation for any one particular product, but just an example. You can find more by searching "gas can spout" on amazon.
You can buy the vents and install them with a drill bit.