Most current sensor technology utilizes water repellent hydrophobic coating to reduce stain mark. Vdust Plus is an excellent alcohol based cleaning solution with fast evaporating quality ideal for removal of water stain, compatible with hydrophobic sensor coating. However, alcohol has poor cleaning quality for most common type of stains such as heavy lubricant and tough organic materials. In the other hand, Smear Away is the most powerful cleaning solution to remove and dissolve even the toughest stains from the sensor surface. More versatile than single liquid Switching liquids enhances cleaning Better value than single liquid Easier to remove tough stain Since it is water based slight over saturation of the swab creates streaks due to the hydrophobic nature of sensor coating. With dual power, if any streaks appears due to Smear Away, either reduce over-saturation of the swab by using less liquid, allow more evaporation time or simply use Vdust Plus with a new swab to remove water streaks. Since simple visual inspection can not determine the nature of stain light or heavy, first start with either liquid, if stain is removed, Stop. Otherwise switch liquid, use a new swab proceed with cleaning. Do not add two liquids on the same swab. Use each liquid with separate swab. Always swab in the same direction. Smear Away Smear Away strong anti fog capability, very strong anti static capability, removes smear on first s