Argosheen closed their doors 2 years ago try tuway 8 inch pads. Not as good as Argo's but will suffice. John@ Bonnet pro is developing a new line of cotton pads and 8 inch is the starting size
The Tuway small pads that I have are (or look like) they are 100% synthetic fibers. These pull off the velcro circle that I so painstakingly glue onto my stair tools' face. Tuway also makes what they call Bullseye pads in a variety of sizes. They are all-cotton, so they don't disturb the velcro. Or you could buy the 12" pads that Challenger sells for use with its larger stair tool.