i think you would be better off to train him to use potty pads . The shower is an odd place for a dog to learn to potty . It may make him a little nervous.
if you can get an ex-pen line it with potty pads on one side and his food , water and bed & toys on the other and keep him in there when you cannot watch him.
put a few potty pads around your house and keep taking him to the pads and say go potty . When he does tell him good and give a treat..
it is really a long process but he will get it |