I use a wide blade chef's knife, like the 2nd one down in this picture.
http://cdn.overstock.com/images/products/L10384638.jpg


I press on it with both hands and kind of rock it back and forth trough the tough skin on things like squash.
one hand on the handle & one on the top of the blade.

I don't know about electric knifes and squash, but maybe that guy had a really dull blades on his.