I had one testicular removed in 2007 due to testicular cancer, now is it safe and healthy for me to pour water in penis hole during bath ?

Reason?: Opening of the urethra is meant for things coming out, not for going in. So if a little water gets into the opening during normal bathing, that is not a problem, however trying to actually get water into the opening may carry with it some bacteria that are normally present in faucet water. It could potentially cause an infection. I wouldn't recommend pouring water into the opening on purpose.