Special footwear - could they be slippers? (4-5)

I believe the answer is:

snow-shoes

I'm a little stuck... Click here to teach me more about this clue!

'they be slippers?' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'special footwear' is the wordplay.
'special' becomes 'snow' (I can't justify this - if you can you should believe this answer much more).
'footwear' becomes 'shoes' (I've seen this in another clue).
'snow'+'shoes'='SNOW-SHOES'

'could' acts as a link.

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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