Risked fish sweet? Do not welcome digging in (6,2,4,3)

'digging in' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'risked fish sweet? do not welcome' is the wordplay.
I cannot really see how this works, but
'fish' could be 'skate' (skate is a kind of fish) and 'skate' is located in the answer.
'sweet?' could be 'ice' (ice is a kind of sweet) and 'ice' is located in the answer.
'do' is present in the answer.
'not' could be 'nt' (synonyms) and 'nt' is present in the answer.
'welcome' could be 'hi' (both are greetings) and 'hi' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?