If you have a stubborn stain on your sensor that won't go away then Smear Away™ is your answer. Specially formulated to protect your sensor as it cleans away oil & grit, Smear Away™ also provides an anti-static barrier to reduce further contamination. It is recommended to use Smear Away™ with Visible Dust MXD-100 (green) Sensor Swabs. All of visible Dust solutions are safe on ITO & non ITO coated sensors. Visible Dust liquid cleaners (Sensor Clean, VDust Plus & Smear Away) when used with visible Dust Sensor Cleaning swabs are safe & effective on ALL DSLRs including newer Canon DSLRs, such as the 400D, 40D, 1D MK III & 1 Ds MK III, newer Nikon DSLRs the D300 & D3 & the Sony Alpha 700 Cautionary Note: Visibledust sensor cleaning solutions & swabs are calibrated to work together to produce optimal & safe results. Please DO NOT USE alternative solutions with our swab. A simple grain of quartz which is found in cheaper solutions are enough to produce an expensive scratch on the low pass filter. Visible Dust solutions are manufactured to the highest standard of quality that is practiced in pharmaceutical industries. Visibledust solutions are calibrated for NORMAL evaporative rates: to keep the swab moist at all time to reduce the risk of scratch to increase the cleaning power, less swabbing more economical to reduce friction by being moist all time during swabbing The potential risk of FAST evaporative solutions used as sensor cleaning are the following: an increase in the risk of damage & stress to sensor coating by using premature dry swab a great reduction in cleaning power by shortening the contact time between contaminants & solution due to the increased evaporation rate of the solution increase in friction by using a premature drying swab, resulting in static charge build up leading to an even greater dust accumulation on the sensor Visible Dust cleaning liquids are intended to be placed on the swab first, so the concern for liquid seeping through the sensor is not valid or accurate. On the other h&, the disadvantages of a generic brand or FAST evaporative liquid used for sensor cleaning may in fact may casue damage to the sensor by requiring repeat swabbing & is not recommended.