I found this a fun little thing to do, so here is a good place for you to get started
It's 2 separate shaders, clean bottle and dirty bottle. Then I am mixing them together on a Multiblend using the same "fingerprints" map i'm using everywhere else. The label also has some stretched out fractal to look like maybe someone tried to wipe it
Here is the graph, you can see how the finger print texture is driving everything, including the blend between the 2 shaders. The finger print texture is always going into a gradient, so that I can manage the levels to get the results I am looking for and each channel can be adjusted independantly a bit. Reflection, Specular, Blends, Mixes, Transparency...etc. My finger print material is also a Triangular projection simply because I usually work like this so I don't need UVs to apply these types of materials to objects.
Here is the project with the textures applied to a sphere, so you can get the scale of the bottle I used. Just scale the texture projections to fit your object.