I think there a lot of ways to skin the cat.
If your going straight salt put some pickling salt in the bottom of a ice cream bucket and use alternating layers of salt and minnows. This dries and preserves at the same time. Your going to want to check them to ensure you don’t dry them too much. They can get very dry this way. Once adequately preserved put them in a zip loc bag with a lightly damp paper towel in the freezer. Pull an hour or two before use.
I like to use a 50/50 mix of borax and pickling salt with a cup of sugar. This seems to keep them more pliable. The key being be sure not to dry them out too much