We used sol-gel hydrosol to impregnate a commercially available cotton fabric with anatase nanoparticles to produce a self-cleaning cotton material. Three different aftertreatment procedures were used to determine the importance of excess sol removal and how the excess sol is removed. This was done by comparing 3 different aftertreatment procedures: plain drying after impregnation at 100 °C, rinsing and consequent drying at 100 °C, and drying at 60 °C followed by a mild hydrothermal treatment at 97 °C. To further compare these aftertreatments, pretreatments were used. The structure and morphology of the prepared samples was analysed by X-ray powder diffraction and high-resolution field emission scanning electron microscopy. The photocatalytic activity was evaluated by the UV photodegradation of methyl orange. It was determined that an aftertreatment method that involves enough excess sol removal is quite mandatory with the overall best result being produced by applying a mild hydrothermal aftertreatment method.