IME, most touchscreens are plastic and are anti-reflective through a coating or a non-glare surface design. An abrasive polish like 105 will likely damage that screen even further. Many touchscreens are an integral part of the LCD display itself and may require complete replacement which may be pricey. You might be able to cut a screen protector, like what is sold for iPads, to size and apply to the screen which may or my not mask the scratch to some degree. This also may affect the sensitivity of the touchscreen.