Here in the UK during the 60s and early 70s I can remember being told to check every packet and tin for the word lecithin before buying it. Rumour had it that manufacturers even sneaked blood into ice cream and I can remember dubs going up to ice cream vendors asking if there was any blood in it before buying. I may have actually done it myself (ahem). The looks of stunned disbelief on the vendors' and customers' faces was hilarious!
My mil once asked a butcher if his turkeys had been bled or strangled before buying one. He burst out laughing and asked her if she could imagine the poor person having the job of strangling full grown turkeys. You really couldn't blame people for thinking JWs were nut jobs!!
Some sisters in my congregation were convinced the powers that be would start injecting fruit and vegetables with blood in order to try and starve Jehovah's people to death, and that would be our tribulation. You couldn't make this stuff up