Yoga mat bag off the needles? Check.
Washer filled with hot water, Soak (citrus scented), 2 towels & a pair of jeans (for extra agitation)? Check.
Yoga bag added to washer mixture? Check.
Sufficient felting time passed? Check. Note the nasty water color. Blah. (This is why we use old towels and jeans!)
Washer set to spin? Check. (This will cut down on excessive drying)
Bag stretched, flattened, and formed before drying? Check. (Again, be sure to use some old towels).