We do a ton of pickled eggs. I use a 2 to 1 ratio of vineger to water and add
Pickling spice
Garlic cloves
Pickling salt
Onions
Pepper
Then I know a fella that works in a green house and grows two types of African chillis ( type of Habinaro's) one is a Zimbabwe chilli, small red and hot and another that is an African pea pepper. These peppers make the eggs unreal. I believe the vineger reduces the heat to a tolarable level but the flavor is excellent.
We made 16 doz last time, seal the jars the longer they sit the better they are.