Somewhere in a late-night rambling on the internet, I came across mention of felted-wool dryer balls. You toss a few in the tumble-dryer and they help to move the drying clothes around, decreasing drying time -- they also help to remove static and to soften clothes without chemical fabric softeners. I'd heard of using tennis balls for this, but when I was having a bit of a late spring clean the other day and came across some decades-old knitting wool that I really have no knitting use for but couldn't bear to throw away, I thought, "well, felted dryer balls, of course!"
This is New Zealand Wool "Wellington", 100% Perendale wool in a handsome heathered green. I had eight skeins -- it's a doughty wool, to be sure, but not really something I'd want to wear near the skin, which is why I haven't done anything with it in the last, oh, twenty-five years. I remember how unusual it was to come across real wool at Super Yarn Mart, which is why I was so susceptible to it when I did -- doubtless the reason that I bought this, plus that it was from exotic New Zealand.
I used the dryer-ball tutorials from Good Mama and DIY Natural, which could hardly have been easier. I wound up golf-ball sized balls, one from each skein (about 4 grams' worth of wool), tied them into a "caterpillar" in the leg of an old stocking, with a tie between each ball, then ran them through a couple of cycles with our regular laundry yesterday, and this morning wound the rest of each skein onto the resulting felted centers.
To continue the sports analogies, the fully-wound balls -- 2 oz. of wool, though generously five or six more grams than the 56.5 indicated on the label -- were about the size of softballs, which felted down to about the size of baseballs.
The only warning I'd give is not to attempt to felt two "caterpillars" in one load of laundry! It took a good twenty minutes to get them untangled and I had this song stuck in my head for hours afterwards. Some of the balls also came out a bit wonky from being smashed up against each other in the stocking, and some of the fibers got enmeshed in the nylon, though only giving it a sort of aura that didn't last through the dryer cycle.
But the wool felted beautifully, with almost no visible lines at all from the strands of yarn, and I expect that after a few loads of laundry, they will be fully felted and quite round.