It is believed that pork scratchings originated as solid bits of left over pig and that, a by-product left over during the process of rendering (thats melting people) pork fat into Lard. Holy shit.
Sometimes the fine layer of hair is removed from the skin by burning; however this is not completely effective and some pieces still have the hair attached and these are blatantly the best scratching, the ones with pigs pubes on them. Yum Yum, or as they say in the black country Yam Yam.
Butchers started selling pork scratchings in the 1930s, and more recently a product called pork crunch has been developed, in which much of the fat is scraped off, resulting in a lower-fat, softer alternative for poofs and queers and that.
If you go to the pub and eat scratching you get really thirsty so you drink tons of beer and get really smashed.