We use products that are safe for wool and silk. We have spent much time and effort to be sure that whatever is used will not have a detrimental effect on the fibres. Most of the cleaning agents that we use are designed for use on the hair. That is, after all, what wool really is. Hair from a sheep. Unlike the sheep, your rug will not grow new yarn, so we need to be careful how we treat them. As for a residue being left behind, we flush the rugs out thoroughly so as to leave nothing but the yarns behind. Many of our clients have chemical sensitivities, so we work hard to remove any residues that may adversely affect them.