Mum loves employing rag mop regularly as cleaner (7)
I believe the answer is:
shampoo
'cleaner' is the definition.
(shampoo cleans hair)
'mum loves employing rag mop regularly' is the wordplay.
'mum' becomes 'sh' (both are used to tell someone to be quiet).
'loves' becomes 'oo' (love means 0 in tennis).
'employing' indicates putting letters inside.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'rag'+'mop'='ragmop'
The alternating letters of 'ragmop' are 'amp'.
'sh'+'oo'='shoo'
'shoo' placed around 'amp' is 'SHAMPOO'.
'as' is the link.
(Other definitions for shampoo that I've seen before include "Liquid that goes to your head?" , "people get set after it" , "preparation for cleaning locks" , "Hair-care product" , "hairdressing" .)