Speck Check

This is the step to check if there are any unwanted spots at your pages. This is probably caused by Bad RAW (too much compression, artifacts), or there are dust on the scanning process.

This is one of the way to check for specks in your cleans.

Click the Adjustment Button in the bottom of the Layer Panel 

It looks like this:

Then Click Levels....  

Rename this new Levels Layer to Something else.

What you need to do now is slide the Grey (the middle slider (grey Slider) or the Black Slider/LeftSlider all the way to the right).

Make Sure this SpeckCheck Layer is the most top layer in the document.

If you find a dust spot, hide this layer and check if it's visible and an unwated spots. You can then clean in with brush or marquee.

When you're done, remove / hide this speck check layer and save your document.

You can make this an actions, because there;s no adjusting here, just slide the slider all the way to the right..

Just make sure when you run the actions, your active layer is the top layer.