Dear R.,
I'd rather listen to fingernails on a chalkboard than listen to a child whine. It makes you resistant and tense because it's one of the most irritating things on the planet.
Fortunately my kids didn't whine much, but I did daycare and had a couple of whiners. I would say things like, "I don't know what whining and pointing means. I can't understand you when you do that."
One kid in particular was a bit of a challenge because if he whined and pointed at the refrigerator, his mom, dad and everybody else would take things, one item at a time, out of the refrigerator. "Is this what you want? Is this what you want? Is THIS what you want?" They'd empty the whole dang refrigerator instead of making him just say he would like some grapes.
It didn't work that way with me.
My kids tried the whining thing after being around it and with my own kids I would say, "Whine yourself on over to the drawer and bring me the spanking spoon."
That stopped them dead in their tracks.
The dreaded spanking spoon.
I never even had to use it.
If I was already in the kitchen I would start rummaging through the drawers pretending to look for it. Sometimes I'd say, "Grandpa, did you see where I put that spanking spoon?" He had dementia, God bless him, and didn't know where his own false teeth were half the time, but as far as my kids were concerned, uh-oh....she's looking for the spoon. They found someplace to go and chill out real fast.
I think you're better off not buying into the whining thing and definitely not giving in simply because it's a way to hush them up for a while.
Pretending you can't hear them just makes them whine louder, in my opinion. Saying you can't understand them is more effective in my experience.
Best wishes and good luck!