Shower bar (4)
I believe the answer is:
soap
'shower bar' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for soap that I've seen before include "Popular TV programme (which cleans?)" , "Cleansing agent" , "made in a bar?" , "TV series of cleansing sort" , "Serialised drama" .)