The frame-by-frame analysis of the heart squishing seems to give away how it was done. The first frame I've captured seems to show Sinbad's fist in two different overlapping poses. I suspect a shot of him squeezing the heart and a separate shot of him squeezing some goo were dissolved together to create the illusion of the heart being squished and spraying goop everywhere. By the standards of the movie, it's actually a fairly well-done effect.

I never liked that part of the movie. Although it's obviously fake, it's still pretty gross for an otherwise sunny and bloodless film. The frame-by-frame scrutiny I had to do to put this comic together pretty much negated any queasiness I'd previously had. (And then, of course, as Gahalyn says, I had to get even grosser with the dialogue to make the mother-daughter joke work, so shame on me.) For instance, it's funny how obvious it is, when you view the film frame-by-frame, how there's a cut at a key moment when Sinbad punches through the zombie king. His fist impacts the chest of the rubber creature, and then there's a cut right at the moment when his arm would penetrate the body. The frame I've included (the one just above the "I'm being possessed..." line) is the last frame before the cut. After the cut, there's a side view and then a second cut back to a frontal view, wherein the hole in the rubber model is fully evident.