I don't use them, and neither does anyone in my church. The question is do they work? It's possible. However, I'm not comfortable using them. It's almost limiting God's power to a cloth.
J.Vernon McGee made a good point in one of his studies. He was diagnosed with cancer some time during his ministry. He told God he didn't want to die yet. He said that he went to the doctors so that God could heal him through their expertise. Without God giving them that knowledge, they would not be able to heal. God healed him of course, but used doctors to do it.
Can He use a cloth to heal someone? Sure. However, what happens when someone takes that cloth with them and they aren't healed? Do they get discouraged and angry at God and turn away from the faith? Unfortunately, this is an all too common trend amongst the faith movement. Men who claim to have healing powers, deceiving multitudes and turning many away from the faith. Our adversary the Devil is wise. He knows how to turn people away from God. "God, You didn't heal me, therefore, You don't love me, therefore, I hate you!" (not that they all say this)
Ultimately, it all comes back to trusting in God and allowing Him to work in our lives. If the time comes when we need healing, either He'll heal us or He won't. Either way, He is still God and we love Him!