I can easily gain 2 lbs of water weight that hangs on for 2-3 days after eating bacon or ham, but I can roast plain pork and add a lot of salt but don't retain water for more than a day.

Now you can get bacon & ham "naturally" cured with "no added nitrates" but they use celery seed/juice that contains as much or more nitrates as the unnatural chemical curng process. Since nitrates are toxic to humans, I would not be surprised if it was the nitrates causing inflammation that appears as water weight gain. But I do have and enjoy bacon a few times a year, usually when other people are doing the cooking. Even when I don't weigh myself, my legs feel heavy with each step, which reminds me not to make a habit of it.