Lightroom isn’t ideal for heavy dust-and-scratch cleanup on film scans. If the scanner supports it, the best solution is usually to rescan with the scanner’s built-in dust/scratch removal enabled, because tools like Digital ICE are designed specifically for this problem during scanning.

If rescanning isn’t possible, you’ll need dedicated restoration software or manual retouching. One community suggestion was the older Kodak dust/scratch removal tool, which was known for this kind of work. In general, these tools can help, but results vary and automatic batch cleanup often won’t fully replace proper scan-time correction.

For the best quality:

1. Rescan with Digital ICE or equivalent enabled if you can.
2. Use restoration software for additional cleanup.
3. Finish remaining marks manually with healing/clone tools in an editor.

So yes, post-processing can help, but for lots of dust and scratches, rescanning with the scanner’s cleaning features is usually the most effective approach.