Washing elephant’s head in circus arena? (9)

'washing' is the definition.
The definition and answer can be both related to bodily activities as well as being present participle verbs.
Perhaps you can see an association between them that I can't see?

'elephant's head in circus arena?' is the wordplay.
'head' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'circus' becomes 'show' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'arena?' becomes 'ring' (I've seen this in other clues).
The initial letter of 'elephants' is 'e'.
'show'+'ring'='showring'
'e' going within 'showring' is 'SHOWERING'.

Can you help me to learn more?