So I have spent some time working them out and find that really anything goes when it comes to felting in the wash. This is so simple and the end results are so fun that for a change..... I actually look forward to doing the wash.
Here is a simple pictorial on how to make felt balls in the wash. My washer is set to run on a GENTLE cold cycle and I don't change to a warm or hot setting to get the little pebbles. Of course, if you wanted to use a warm or hot setting to your wash, I bet they would felt faster. Use your regular washing detergent and load your machine as normal adding these little steps.....
Have a few little balls of wound roving or picked fluff ready. One pair of jeans will do 2 pebbles.
As you put in your jeans in the wash, fill each front pocket with a tangerine or tennis ball size of fluff. Make sure they are stuffed to the bottom of your pocket and if you have smaller pockets fold the jeans in half with the front, stuffed pockets on the inside. Oh and do not use the little pocket on the front; for some reason fiber does not like to felt in there.
After a GENTLE cycle in the wash, you will have something similar to the ball of fluff above. Notice that you can still see the seams where it was wrapped. Do not worry and put your little compact ball back in the jeans pocket and toss your load of laundry in the dryer as normal.
When your jeans are dry, you will have a lovely round pebble! Note, I have had a couple of pebbles come out of their pockets in the dryer, and the end result was the same. A lovely felted pebble:)
From left to right or top to bottom: Ball of fluff, out of the wash and completely felted.
The end result, fun little felted wool pebbles! Notice the little purple tape yarn in one pebble! It is a nylon yarn and the I had no idea it was in the pocket when it went through the wash. Love that it is completely attached to the pebble! Wool and angora goat locks felt great as well. They felt slower than the other fibers so are a great way to add texture!