You attempt to raise a corner of the rug and kick the bottom side, should a cloud of dust flies off, you no doubt know it's enough time. Spray solutions are used in pre-treating the rug. Many grocery stores rent the cleaning equipment and cure. There are multiple strategies of dry cleaning a rug. https://dmzvnayqnvbcq4qjwl7awewt3gtexkx25tafvyhx2zj7fttwbk4q.cdn.ampproject.org/c/s/Www.lawdw.com%2Fbbs%2Fboard.php%3Fbo_table%3Dfree%26wr_id%3D552996