I've not ridden them, but have seen an example of those Cinelli pedals in person. The mechanism is quite simple, you slide the lever behind the spindle and depending on its position the cleat is either locked in place or free to slide.

I'd guess that riding with these would be much the same as using toe straps, only difference being that the binding mechanism operates on the cleat instead of being a strap that goes around the outside of the shoe.