I've been recycling, felting wools for years. I use a hot wash, with detergent then a Cold rinse. Toss in regular setting dryer. Comes out great. I've never had to ( boil). Felting is a process achieved from the agitation, detergent, hat & cold. Sometimes a longer cycle is necessary on loose weaves-- I just keep an eye on the washer, catch it before it starts to drain and reset a opulent times. To see if your wool is felted enough, when it comes out of the dryer cut a small piece from an edge, if the edge doesn't fray it's ready.if it does fray it needs more felting.