I never had any luck getting birds to use dryer fuzz for nesting, even when I put it right next to the bird houses. It’s not that they’re picky; I’ve seen them use strips of clear plastic, woven in with the grass.
Actually, shedding in cats is triggered by changes in the amount of sunlight reaching the earth. So while they do some shedding all the time, the majority of it happens when seasons change, in spring or fall.
Temperature doesn’t really have much to do with it*, especially as most cats live indoors, at roughly room temp all year round.
But dryer lint works better as stuffing, like for a pillow, or stuffing inside a quilt, than spun into yarn. And it tens to pack down, not stay fluffy. The commercial stuffing is more consistent & easier to work with, and a lot less work to obtain.
*Except that average outside temperature changes with the seasons, too. But it’s the light, not the temperature, tha is the trigger.
I met a couple a few years back and they were saving the undercoat from their 2 massive Newfies to knit sweaters for their infants. I don’t know how that turned out. I’ll have to find out.
Dryer lint also makes an excellent tinder, for starting campfires. It’s the only material I’ve ever seen anyone successfully light using flint and steel. I’m sure there are other materials that are even better, but they’re not as readily available.
If you have natural sheep wool - that is, with the fat still on it, so it slightly repels water and regenerates with fresh air - it will always smell more or less strong with lanolin (wool fat).
Carding is done not only for cotton, but mostly for wool, to bring the fibres into one direction and pull out dirt, foreign bodies and too short fibers.
You still need either the right consistency - like wool, which “hooks” into each other - or a minimum length, or both.
Since dryer lint is mostly short fibers, I would recommend felting or pictures and similar.
Does the dryer lint smell after chemicals you use during washing/ drying? (Anti-static sheet)?