Just stop the boat!
That's all. Just stop it. That damn figure of 8 or gybing, or big circles, and all the rest is total and utter nonsense. Just stop the boat: sail into the wind, or if engine on full astern. If no engine on stop the boat, get the engine on, get the sails down.
Chances are the MOB will have swum up to you before you've opened the swim platform.
This is really dangerous advice, for the following reasons :
If you are sailing a larger, heavy boat, a stop into the wind will have you at least a hundred feet away from the MOB, if not more. In rougher conditions and/or cold water the MOB will be doing everything he can to stay afloat, and will not be in a position to swim to the boat. Also if he is wearing a life jacket the position they put you in makes it impossible to swim. So your plan relies on them taking the life jacket off. Under these circumstances 100 ft might as well be a mile.
The previous owner of my boat ably demonstrated why you do not start the engine when you are sailing and have an MOB. He sucked a line into the prop, so then you had : a disabled, sinking boat, AND an MOB in trouble. The MOB couldn't swim to the boat. Thanks to the coastguard the guy JUST survived, and it was a close thing. There is too much going on to safely drop all the sails and start the engine.
That's why you are strongly recommend to : if you are sailing, keep sailing. If you are motoring, keep doing that.
They teach the figure-of-eight because it's it's a universal technique that works on any point of sail. They've actually looked at what really works. There are other ways to return to an MOB that require more skill and include a gybe. These are good to learn. But the key word here is RETURN. The idea that you can just stop and relax while the MOB happily swims over and jumps onto the boat is ridiculous.
If I ever fall in the water I really hope not to see the boat REVERSING at me under power.