If those are the same ones that Costco sells in a 3 pack (neon colors) with a big mf drying towel, I did not like them at all. I ended up returning them. If I had to have something similar, Walmart sells a very similar kind but lined with a plastic inside it. The problem I had with the Costco muppet head mitts was that it was lined with a cloth material on the inside, and after the first wash in the machine it was a complete mess inside. I also found that the mitt was too heavy (when wet with soap solution) for my liking and I used more solution than I really wanted to.
I like wool mitts, but I hate how they shed and sometimes they'd fall apart faster than I wanted. I was using
Meg's mf mitt and the Eurow mf mitts for awhile, but then discovered the sea sponge. The sea sponge was great, but I can't justify paying full price for them. They're also too gentle IMO and sometimes I found myself applying way too much pressure just to clean certain trouble spots.
For the last couple of months, I've been using the grout sponges from Home Depot. Rinses cleanly like the sea sponge, more durable than the sea sponge, cheaper than the sea sponge, and provides just the right amount of cleaning for me. Mf mitts never rinse completely clean like sea sponges or grout sponges so I found that once I was done using it on 1 car, I put it in the wash bin and grabbed another pair. With sponges, I just have to agitate them against the grit guard and they're good as new. It's almost impossible to tell a new sponge from an old sponge besides the cuts you get from a used sponge.