Bars want lean baloney sandwiches (10)

'bars want' is the definition.
The definition and answer can be both to do with social activities as well as being verbs in their -s form.
Perhaps you can see an association between them that I can't see?

'lean baloney sandwiches' is the wordplay.
'lean' becomes 'list' (both can mean to tilt).
'baloney' becomes 'blacks' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'sandwiches' is an insertion indicator (goes on either side like a sandwich).
'list' inserted within 'blacks' is 'BLACKLISTS'.

Can you help me to learn more?