Sawdust "fixes" nothing. It mixes with gear oil and that sticks to the housing of the rear axle or manual tranny and creates a sound barrier to muffle the whine. It also chews up in the teeth and adds a cushion to fill slack. My dad bought and sold heavy equipment for years and learned the trick from his father many years ago at the old auto auctions. They used to use banana peels also.
I've patched a few radiators with black pepper on old farm trucks and even once on a dirt track car that was leaking at a seam. And if you have a rod knock and want to get rid of the car, 80w gear oil and 50w mixed half and half will muffle it and get the oil pressure up too. Just make sure engine is warm when they hear it because it may knock on initial start up.
I had a Dodge shadow 3 yrs ago that tossed a head gasket on me and I really needed something to trade in so I torqued down the head bolts, changed oil, loaded it up first with copper stopleak, blocked both radiator hoses with freeze plugs shoved in the them drilled with 2 , 1/8 inch holes and trailered it 3 blocks from the Hyundai dealer. They allowed me $1800 for the car. He even took it around the block!
As far as the exploding paint booth, it is the spark from a light source or fan in the booth that "can" cause it. More so likely with older paints that had more flammable contents but it is still possible. Just not as probable.