Nipple stimulation can definatly jump start labour, i personally would avoid it as baby will only come when he/she is good and ready but if done, its got to be done safely, 15mins on each nipple then swap and only do for an hour no longer, too much can
effect baby as its forcing labour and can be too much for little 1 but through my own experiance it brought on the most painful braxton hicks ever, had my son 3 days early, wether it was the stimulation that helped i dont know, but out of my 3 pre