Rather than learn how to deploy speed brakes in flight, why not learn how to fly your aircraft at the correct airspeed? I've never flown the 737 but I have flown several other Boeing aircraft as well as many other types.
In my experience, if you control your airspeed and execute the flare properly, the aircraft won't "float", speed brakes aren't necessary or desired, and everyone will be happier if you fly on speed. It takes a bit of concentration, but it really isn't rocket science.
I'm retired now, but I can also tell you that had I ever deployed speed-brakes to force my aircraft on the ground I'd most likely wind up doing a rug-dance in the chief pilot's office. My airline strongly discouraged cowy flying.
I don't know the statistics, but off the top of my head I can think of more landing accidents caused by flying too fast than flying too slow.