Might be just outside your threshold but the divestment campaign against South Africa is credited with helping to end the system of Apartheid.

https://en.m.wikipedia.org/wiki/Disinvestment_from_South_Afr...

The disinvestment campaign did very little except transfer ownership of some of the largest companies in the country to South Africans and I would assume the bulk of that would have ended up in the hands of the politically connected.

Sanctions also didn't do much. There was a thriving market for goods from overseas. Even now more than 30 years later there's a tradition of giving your relatives a list of things to buy when they travel internationally. Sanctions probably indirectly hurt poor South Africans but never anyone politically connected.

What really hurt and forced the Apartheid government to start seeing sense was the IMF ending all loans. http://kora.matrix.msu.edu/files/50/304/32-130-4C3-84-africa...

I think the Swift banking system ban proposal for Russia would be more likely to work.

Ban SWIFT get CISP. I wonder how printing USD will look then.

Whether they “work” depends on the goal I suppose.

If the goal is to get misbehaving countries or leaders to change their behavior, I’m not aware of any examples, not matter how far back we look in history, where they worked. Plenty of examples where sanctions are imposed and the behavior gets worse.

If the goal is to weaken a country (which could be a good thing, if that country is belligerent), I think there are plenty examples of that working. It can have the unfortunate side effect of also impoverishing the ordinary citizens of the sanctioned nation.