With some assistance my 4 year old and 6 year old were able to make their own wet felted soap.
My 4 year old really loved getting sudsy! My 6 year old did not. If you have a kid that loves rolling up their sleeves and getting dirty (in this case, clean!) this is a great activity.
The wool roving for wet felting is available on line. The roving comes in an array of colors. You only need an ounce each of 3 or 4 colors to cover several bars. I just ordered some Ecosoft Roving from Weir Crafts for $2.25 an ounce. There are many other options available on line.
Setup: Cover your table with a towel. Have some extra hand towels nearby.
Old panty hose or knee high, bar of soap, roving, and container of very warm water