Depends, the theory is spicy foods give you diarrhoea(irritating the small bowel) which in turn irritates the smooth muscle of the uterus. Same with some laxatives. So some people find it works if they are not used to spicy foods. Something like acupuncture is more proven though, or LOTS of unprotected sex (prostaglandins in semen are the same as what they can use to induce you) but only present in very small amounts.
No, spicy food does not induce labour...
No. Nothing will help. Whatever anyone claims will, is not guaranteed. They are all old wives tales. A membrane sweep and doctors intervention might help, but not pineapple or driving over railroad tracks or really anything will help. Seriously seeing all these posts and everytime it's the same thing. So straight up no it won't.