This tool allows allows you to quickly scatter a layer of geometry dust on the surface in a very realistic way. As it uses instances, you can scatter millions of dust instances without using too much memory.

https://blendermarket.com/products/procedural-generator-bundle

This is far better them using just textures because it allows you to apply the effect to an entire collection and this is not resolution dependent, so you will get crisp renders even on low res models.
Using particles to do this will for sure make you waste a lot of time and even them you will not gonna have the same result.
You can go really crazy with this, because the tool has settings to show a lighter version on the viewport so you can work on this without having performance issues.
It comes with a control to determine lower the amount of instances on the viewport while keeping the full density at the render time.
You can mask a region to preview the full density in an area without exploding your pc while you are working and it has a checkbox that let you to show only basic points on the viewport, with also increases performance.

You can remove particles that are not visible to the camera.

You can even use a roughness map to control this

To use this you just need to append the "DustGen" to your scene while selecting the "DUSTGEN" inside the "NodeTree" folder. Apply the transformations of the object and add the Geometry Node "DUSTGEN" modifier to your object.

You can follow the video bellow to see how to use it.