I found these at Downers Grove Auto Parts (now NAPA). They are an excellent addition to your boot. They have a smooth side and a coarse side and work great for removing dirt, oil, and grease after working under the hood. They are pre-moistened and come 30 towels to the container. I bought my first containers for $2.99 pre NAPA. The last time I saw them they were 4.99. I haven’t seen them at any other auto store.
-- John Schroeder