Usually you use 浴びる for showering or bathing (not too sure about bathing) right? And you use 洗う for washing in general right? Can you ever use 洗う in a shower/bath scenario like my example below?
例:シャワーをあびた時、下の所が特に洗った。(disclaimer: sentence might contain errors)
While I was showering, I especially washed my nether regions.