Plug in hole initially, I saw off bit of gravy -- with this? (7-2,6)

I believe the answer is:

washing-up liquid

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'gravy with this?' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'plug in hole initially i saw off bit' is the wordplay.
'initially' says to take the initial letters.
'off' indicates anagramming the letters.
'bit' becomes 'quid' (quid is a kind of bit).
The first letter of 'hole' is 'h'.
'plug'+'in'+'h'+'i'+'saw'='pluginhisaw'
'pluginhisaw' with letters rearranged gives 'washingupli'.
'washingupli'+'quid'='WASHING-UP LIQUID'

'of' acts as a link.

Can you help me to learn more?

I've seen this clue in The Telegraph.

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