Can you get epididymitis from washing a penis in dirty water?

Very unlikely...: Epididymitis in the young is still most commonly caused by STD-related urethritis retrogradely extending from vas deferens to the epididymis. Washing and soacking in dirty water alone would not cause epididymitis, but poses some risk to contract certain bacterial or parasitic infection although luckily our natural barrier & systemic defense mechanism in generally healthy persons have enough power.