
You absolutely can get that lens clean and keep it scratch free. I would grab Altura Photo cleaning kit since it gives you an alcohol free lens spray and a solid hand blower, which is exactly what you need to lift grit before you ever touch the glass and then clear stubborn smudges without streaks.
Here is a quick routine that protects the coating and avoids scratches. - Start with the blower to remove loose dust and sand. Avoid canned air. - Lightly sweep with the soft brush to lift anything left. - Put one or two drops of cleaner on a clean microfiber or lens tissue. Do not spray the lens. Wipe from center outward in slow spirals. Finish with a dry area of the cloth. - For fingerprints that fight back, use the lens pen tip with tiny circles, then a final pass with the microfiber.
A few travel tips that help a lot. Keep the lens cap on between shots. Consider a cheap UV or clear protective filter as a sacrificial layer. Store your microfiber in a small zip bag and wash it without fabric softener. Never wipe the lens dry or with a T shirt.
Do this only when needed and that DSLR will be ready for many more firsts and Grand Canyon dust storms.