Sometimes certain things can contaminate your pads. And there is nothing you can do to effectively clean them. Though there are plenty of remedies that others claim anecdotally that solved their issue. You can look and try them if futzing around with such is what you want.

I'd make certain the rotor is within whatever limits SRAM specs for it. And then get some new pads. And if a new rotor isn't a burden for your wallet, go ahead and replace it too whether the old one is worn or not. Make sure that the pads you get are for the rotor you get. Some rotors aren't made for certain types of pads, resin, metal and etc.