|30 years of progress:|
At Home Depot there were four different replacement alternatives, each sturdier than the broken one I had, plus machines that could probably unplug all the toilets in the house at the same time.
I settled on a cheap but durable polyethylene model, which had double bellows for "extra force." (We'll probably all be on waterless waste systems--ugh--in 15 years, so one shouldn't make a huge investment in today's toilet technology.)
It did the trick in less than a minute. If more of life's emergencies could be solved for the six dollars spent on this one, the world would be a much happier place.