The B737 Landing Roll - F/O handling and Captain Hovering..
Nobody that cannot land and end the landing roll safely in different conditions should be on the flightdeck operating any aircraft
The instructor simply gives himself a 15 knot tailwind on a short wet runway and deliberately makes an unstable approach by coming in high and fast (Vref + 15), floats in an attempt to make a smooth landing and after touch down applies all retardation devices. Done "correctly" the aircraft slides off the far end of the runway and into the localiser aerials along with mud.
This little practical demonstration shows the pilots under training what can happen if they persist with an approach that obviously requires a go-around. Having actually observed at first hand that even the instructor cannot land safely under those conditions, it is hoped that the crews under training will always remember that scenario in the future. If in real life they then observe a similar scenario unfolding, they are more likely to insist on a go-around.