Such suicides have historical antecedents, and they have worked.

Within Celtic countries, and perhaps within the entire Indo-European spectrum of culture, fasting against a more powerful person was the ultimate in protest. Quite simply, you sat outside their dwelling and starved yourself until either you died or they rectified what you saw as an injustice against done to you. It was a form of cursing, and often the only such form of protest available to the weaker person. This being done by widows was thought to be particularily powerful.

I have noted the Buddhist monks in Saigon earlier.