Yes, TotalBeginner, forgive me but I fear you are wrong. In fact the drag from a stationary prop is much greater than from a windmilling prop.
Absolutely incorrect.
A windmilling propeller isn't just a moving propeller. It's a a moving engine, and the engine is absorbing energy from the slipstream rather than imparting it to the airflow through the propeller disc. The drag from a windmilling propeller can be, and often is, greater than a solid plywood disc out there of the same diameter as the propeller arc.
That said, unless you have substantial excess altitude with which to play, attempting to decrease airspeed enough to allow internal engine drag to stop the propeller isn't in your best interests. You'll likely end up wasting time and altitude that's best spend setting up for a forced landing, communicating distress information, etc. In attempting to slow, you increase your rate of descent, and risk a control loss with a preoccupation of stopping the propeller.
In propeller driven aircraft, I've had 40 or 50 engine failures over the years, many of them in radial engine airplanes. I've had ten or so in single engine piston airplanes, and two years ago two engine failures in turbine singles within a three month period.
In the first of the two most recent single engine incidents, (the airplanes were powered with a Garrett TPE-331-11 powerplant), the engine surged between no power and takeoff power rapidly, and the failure occured over a forest fire at about 300' AGL in a heavily wooded area. I was preparing to put the airplane in the trees, but was able to restore power, or partial power, and followed a two land paved road off the mountain to an airport about ten minutes away.
In the second incident, the failure occured at a lower altitude in a canyon (which was also smoked in and on fire), and resulted in a forced landing on the mountainside. It was a different airplane than the first. The propeller did not feather, and continued to rotate until I was on the ground. A turbine bearing seal failure allowed all the engine oil to be lost overboard; the power section of the engine continued to operate normally with normal temperatures, but no torque was available as there was no oil remaining to actuate the propeller.
With respect to a "real" engine failure, you need to be wholly convinced that it's never a matter of if, but when. The time to handle an engine failure isn't when the failure occurs, but long before that. Plan, rehearse, study, prepare for the time it may occur. When you line up on the runway, be prepared for the failure at any point in the takeoff, and know what lies beyond the departure end of the runway. Know your procedures, speeds, and most important of all, know your cockpit blindfolded. Be able to find seat belt releases, fuel shut-offs, door handles, window or canopy releases, and emergency equipment upside down, with your eyes closed, underwater...know how to get out under unusual conditions or circumstances.
Be mentally prepared. Not just with the simple idea that it could happen to you; be spring-loaded to respond because you fully expect a power failure, fire, control problem, etc. A normal, uneventful flight should be a pleasant surprise.