Long story short, George my oldest got an electrical shock from a hot wired fence straight down the clippers onto his nose. (don't ask, hubby did a bad thing LOL)
He was never that great about having his muzzle clipped, but that just sealed the fact that clippers are indeed evil.
You've posted some pretty wacky ideas that your MIL has given you, but she's not out in left field this time, neither is your idea.
Also, pick your time. An hour or so after breakfast or lunch when her belly is full and she feels lazy is good. Don't do it close to feeding time.
There's also nothing wrong with rewards. George is a food hog, so I would load my pocket up with flax treats and give it a go. Even if I got the clippers anywhere near him he got a treat. He's still not a 100%, but for the most part he'll suck it up as long as the treats hold out and I pick my time.
Go slow, start on the legs if you have to. Make sure the clipper blade is nice and sharp so your not pulling on hairs.
Here are a couple of pictures from 2 years ago when I was just starting to get him over it. George has the halter on and Kooter doesn't.
Here I've just placed it on his blaze:
Here I'm clipping Kooter and George is pretending he doesn't notice. LOL
George is still trying to hide:
Here I'm reaching under Kooter to touch George.