I have had similar 'noise' after riding through puddles, for me it was that one side of the caliper was very close to rotor. Although I had pads aligned so they weren't catching, crud that was getting onto on the caliper from puddles/being thrown off the pads/rotor, on the side the rotor was entering was catching/making the noise, rather than anything on the pads. Shifting the caliper over a bit helped. Hope this makes sense.
I have had similar 'noise' after riding through puddles, for me it was that one side of the caliper was very close to rotor. Although I had pads aligned so they weren't catching, crud that was getting onto on the caliper from puddles/being thrown off the pads/rotor, on the side the rotor was entering was catching/making the noise, rather than anything on the pads. Shifting the caliper over a bit helped. Hope this makes sense.