Well, possibly. Such a claim is asking for punishment - like asserting that you've perfected your golf swing, or tennis serve. But I may be on to something.
Various recipes tell you to rub vinegar, as well as salt, into your pork rind. At the weekend, I tried it. First, I rubbed table salt into the rind, left it for 15 minutes, and patted dry the rind with paper towels. Then I rubbed in about a tbsp of white wine vinegar, grinded over sea salt, and - as I did last time - put my 1kg joint of belly pork into an oven pre-heated to the highest temperature.
After 40 minutes, I knew it was going to work. The crackling was dry, crunchy and golden. We could have eaten it then; but I cooked the pork for a further 2 hours, 45 minutes at the bottom of the oven at gas mark S/130C.
Why it works, or why lemon juice helps to crisp the skin of roast chicken, I am not sure. Something to do with the fats dissolving in the acid, I suppose.