i dont see why car disc brake cleaner wouldnt work , but somtimes automotive products can be of a higher concetrate . buy the sounds of things , id get the disc mount face (a circular cutting bit cuts the face of the disc mount flush with the axle so it will run true) , all good bike shops will have one , id say id lend you mine , but would cost a bit on postage! maybe push the pistons back into the caliper to re-lube the piston (be carefull doing this and take the pads out as you dont want to damage the breaking surface , put old pads in or somthing to stop the pistons getting damaged. hope you get it sorted mate