Sorry to say, but if you had preservative on the rotors it will have ruined your pads.
Had it myself quite a few years ago.
After I was advised to clean the rotors off I reused the same pads and ended up cleaning the rotors a second time and fitting new pads.
By the way the best thing to clean them off is paraffin (kerosene) as it is VERY slightly abrasive. It will really get into the machining marks.
Then give a final clean using petrol to get rid of any residuals.
Don't forget the edges and the hub.