Usually the visible "sensor scratch" is actually on the protective glass/filter in front of the sensor, not on the sensor itself. You may be able to remove loose dust with a blower, but with a scratched surface there is extra risk in trying to wipe or wet-clean it yourself, especially across the damaged area.

The safest advice is to have it inspected by a repair specialist. If the scratch is on the cover glass, that glass can often be replaced without replacing the sensor itself. So yes, dust can potentially be dealt with, but DIY wet cleaning on a scratched sensor cover is not the best first step. Professional service is the recommended route.