I’ve never blocked a hat since most seem to look ok without it. Scarves I block on the ironing board by pinning them down and using steam on them. I then leave them to dry. The cats make blocking on the floor pretty much a no-go. One of them likes to claw. She likes it more when I see her and make all the funny loud noises and chase her. Sheesh!!
I’ve only blocked my Clapotis, but I just soaked it, squashed the water out of it, laid it out on the floor on some towels and walked away. Took about 2 days to dry. As for the furnace, it’s a good thing I didn’t try to re-light the pilot light. the thermocouple was broken and when the repair guy lit the pilot, at first it didn’t light, then it back-fired. Whoosh! big flames coming out of the furnace. All fixed now….
I ‘ve knit a couple of fair-isle type hats that had to be blocked; I washed them, rolled them up in a towel that I stepped on (squeezes out more water that way), smoothed out the hat, sandwiched it between 2 flat plastic bags, and put a heavy book on top. I also do the scarves on the ironing board thing. However, all my ribbed and cabled scarfs eventually reverted to their “natural” shape with wear, and didn’t stay flat.