It needn't contain Russian tea (7)
I believe the answer is:
samovar
'it needn't contain russian tea' is the definition.
The definition suggests a singular noun which matches the answer.
'it' is the wordplay.
I cannot quite understand how this works, but
'it' could be 'sa' (old-fashioned abbreviation for sex appeal) and 'sa' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for samovar that I've seen before include "tea maker" , "source of drink" , "Russian water boiler often used for tea" , "Spoken" , "Russian tea-urn" .)