A member of the Australian Ozgrow garden forum had some unexpected seed set on his walking Onions last spring and has recently sent me some seed, about 40 arriving today.

Needless to say that I am very interested in seeing what comes out of them, but have very limited experience in germinating onions. Wondering if anyone here has any experience with these and is prepared to offer any guidance.

I've never germinated walking onions, but I do grow all my onions by seed.

The traditional seed starting mix, with a good initial soaking does the trick. Keep the pot in a cool place.

I don't do this next part often, because I don't find it necessary, but you can soak them in a wet paper towel and stick them in the fridge for 2 weeks before planting.

That's a great score Whwoz - seeds of walking onion are extremely rare.
I am not the world's greatest expert but onions, leeks, bunching onion and other alliums get the same seeding treatment here - put them in a small flat of potting mix covered with about 5 mm of fine soil or compost, keep moist until they germinate, and keep them under lights once they do, or give them outdoor or greenhouse daylight if you can. I've read two weeks, I think they're usually starting to come up in about one week though if your seed is fresh. But don't be disappointed if you don't get 100% germination from the walking onion as I've read that even when seeds are obtained, they aren't always viable.
The alliums from seed are fine in a mass planting or close quarters until they develop two leaves, then they can be moved to their own cells to size up before planting out. I found they do better here if I size them up in 9-cells with a bit of bone meal to encourage roots. I would definitely pamper anything that germinates from your rare seeds!

Sounds like fun! Onion seed doesn't remain viable (for me) for more than 2-3 years, so go for it!

I'd suggest cold treating some but not all. I've had better germination in some onion varieties without chilling them.