How would you save someone's life with an ear of corn?

Jam it up his anus to shock him back into life.

No lube.

If they were starving I’d roast it and feed it to them.

Lop the end off at an angle to make a wedge. Cut a notch in the remaining piece to use as a tool to remove an obstruction or as an airway.

I would get help. As Mark Antony said in Julius Caesar…

Friends, Romans, Countrymen – lend me your Ears (of corn)

Us it for chest compressions during CPR.

As an object of torque when applying a tourniquet.

Tied to end of a rope as a water rescue aide.

To pack a gaping would to staunch blood flow.

Slower, but less eye watering than @ragingloli’s suggestion, I would plant the seeds and grow enough corn to feed a multitude of starving people.

Toss a bunch to a drowning man to keep him afloat.

feed them

and the winner is…. @stanleybmanly!

Give a man a kernel of corn and you feed him for a minute.

Teach a man how to plant corn and he dies waiting for it to grow.

Use as suggested in the first answer on the dog that has attacked him.