Which methods can be used to exercise the penis to make it harder and larger

Patient's question:

Is there a way to exercise the penis to make it harder and bigger? Is there a problem with washing the penis with shower gel? I am nineteen years old

Doctor's answer:

First, sit in a kneeling position and adjust your breathing. Then, begin to slowly inhale using the strength of your abdomen. As you inhale, gradually tighten your anus, imagining that you are drawing air into it. Once your abdomen is full of air, compress it as if you are squeezing the air back. Next, expand your abdomen, as if pushing the air from your back up to your head. When exhaling, slowly push the air towards your chest and lower jaw; at the same time, gradually relax the tightened anus. After exhaling completely, if you compress your abdomen, the degree of contraction in your anus will be tighter than expected. Repeat steps 1 to 4 for about ten minutes to make the transition between the sympathetic and parasympathetic nerves smoother.