The phrase "to use the bathroom" means to go to the restroom in order to relieve oneself or perform other bodily functions such as urinating, defecating, or washing one's hands.
Secondly, even if you do catch them at the right time and punish them, they will think you are punishing them for using the bathroom in front of you. (potty-train-dogs.com)
Oh, but the whole washing your hands after using the bathroom thing? (bonappetit.com)
This can be a reality (most of the time), provided you follow these tips when using the bathroom spot. (totallygoldens.com)