This DOES sound familiar. No need to panic.
It sounds like the cavalier reverse sneeze. I'm not 100% on the science of it, but the chocking/snorting sound is caused by the shape of the cavalier palate or snout. It sounds worse than it is.
Some people have found success in ending longer episodes by forcing the dog's nose down toward its chest for a few breaths. Others finding forcing the nose upward works, too. It depends on the dog.
My new rescue, Willow, has more issues with this than Cedar. It freaks her out; she tries to run and hide. It helps to keep the animal calm by staying calm yourself. And that will be easier when you know the dog is okay, it isnt choking or anything, and you have techniques to do to help.
Cedar (tri), Willow (blen), Holly (ruby), & Bella (blen)