It turns out I may have trained my family too well.
It took no more than 5 loads of laundry to get this dang swatch through the washer and dryer. Everybody kept pulling it out of the hamper (including my 4-year-old, who told me “Knitting doesn’t go in the laundry”). Which, I suppose is a good thing, in the long run. It’s nice to know that they all know how to treat knitwear.
But anyway. I made a swatch from Berocco Vintage. It’s half mistake-rib and half stockinette, worked on US5s. A nice sweater-y swatch. Nothing too out of the ordinary.
I took gauge and got roughly 5.5 sts/in in stockinette and mistake rib.
So, now it’s into the wash and…
Well, that felted up! It’s actually super soft and squishy, and I’m sure my 4-year-old would be very into a sweater made from this felted fabric. (They can truly never be “too cozy.”)
Just for science, I took gauge again and got basically 5.5 sts/in. Not much different gauge-wise, but the fabric definitely looks different.
I’m tempted to go ahead and knit up my first-ever felted sweater, but I wonder how much long-term wear a sweater like that would have. Would it felt more every time I washed it? Or, would I have to hand-wash a sweater for a preschooler?
Have you ever planned a big felted project?
On the Needles 
I’m impressed at your well trained family. My husband nearly became my ex-husband when he put a particularly nice pair of hand knitted socks in the laundry . It was the fist time I’d worn them.
I have a washing suggestion: 1) don’t feel obliged to wash so often, yeah so its a little bit dirty. 2) wash woolens with no agitation, soak in cold water with a small squirt of liquid dish detergent ( do this in a bucket) push up and down a couple of times. dump into the washer and spin out on gentle (no agitation). add cold water and let it sit for a rinse, push up and down with your hands, spin out. repeat rinse. If you feel the need to wash often then I would skip the soap and just do a deep rinse. Wool has a natural property to repell dirt, think of the sheep, they just shower off in the rain and keep pretty clean.