Anyone heard of this, or experienced the proof?
Edited to Add: Thanks for the replies, everyone! I was aware of most of the other tricks like washing off canned beans, and I also like to add cumin. A little more research yielded the recommendation to add vinegar only in the last few minutes of cooking, rather than at the beginning - this may avoid the issues some of you had with them ending up tough. Another suggested that when cooking dried beans to add a quarter cupful of apple cider vinegar to the water that they soak in overnight, then rinse them thoroughly before cooking.
For those who have had issues, it may be worth a try, particularly if cooking for those who aren't heavy bean consumers. I will try it myself next time and see how it goes.