I want to know if you have cooked your pork to the point where you can 'pull' it can you further cook the rillette in fat / lard in a similar way to what a confit is done or is the fat just poured over the the cooked pork when you seal the meat in the container?
Can you use pink salt (Nitrates) in your cooking process so as to make the rillette store for many months?
Rillette is pork cooked in fat (not really confit, but close to).
Most of what I've seen on the internets is that you can freeze the rillette for longer storage; if not, keep at most for 30 days in the fridge.
You can pour a little bit of the fat on top of the rillette in the container, mostly for extra flavour, not for long term conservation.
I don't know enough about pink salt (Himalayan salt or the Pink curing salt ?) to help you there.
To the first part of your question: Rillettes are cooked until the meat is falling apart tender, then it is strained from the fat, shredded, and then stored with some of the liquid fat added back.
It is likely possible to increase the shelf life of rillettes with the use of nitrates, but many recipes suggest a shelf life of 2 months, and I've seen as much as 6, with no nitrates. As preserved meats can grow some stuff that is seriously hazardous to your health, I would stick to a recipe and not just chuck stuff in. As many home cooks balk at preservatives in home cooking, I suggest you look at industry-oriented publications for recipes.
