Here's the original picture.
Here they are, after the first round of cleaning with carpet cleaner and Scrubbing Bubbles.
Still dirty, but at least you can see the embroidery a little bit better! I was going to try soaking them in Woolite, but the stiffening in the soles is cardboard! Nope! Can't dunk them into anything wet! I just stuffed the end of a washcloth into the toe, sprayed carpet spot cleaner and Scrubbing Bubbles on them, and rubbed with a damp cloth.
By the way, Scrubbing Bubbles in the aerosol can is great for cleaning carpets! Before we traded our old camper in, I cleaned the carpet with Scrubbing Bubbles, and used an old towel soaked in Lemon Pinesol and hot water to scrub it. It looked brand new (and the black marks my husband tracked on the carpet disappeared!) when I finished, and the camper smelled wonderful, too! In fact, somebody bought the camper as soon as we traded it in!