As zigzig dry brines the onions, we wet brine, which entails leaving the peeled onions/shallots in a mixture of 2oz salt to one pint of water to one pound of onions overnight (making sure the salt is dissolved).
Next day rinse, dry and pack in jars. You can then add just plain malt vinegar or a mixture of spiced and malt. If you prefer a slightly sweeter pickle you can add part sherry vinegar.
We make our pickled onions in September/October to be ready for Christmas. They do take time to mature.
I think you need to be patient. By all means pull a few, peel them and pickle them, but they are not going to be ready to eat next week. Probably not even next month. Oh, and when you peel them, wear goggles, because they will be sooo strong. Eye wateringly so. ;D ;D
As I say, try to be patient. Leave them in the ground to mature. They will be much better for it.
Enjoy them at Christmas.
valmarg