The most common and most likely answer to this crossword clue is the 6 letter word LACING
I've seen this crossword clue in The Daily Telegraph
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Buddy explains!

The straight part
We know that "Net effect/severe beating" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case net effect/severe beating = lacing.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does LACING mean?
LACING verb- To fasten (something) with laces.
- To add alcohol, poison, a drug or anything else potentially harmful to (food or drink).
- To interweave items.
- To interweave the spokes of a bicycle wheel.
- To beat; to lash; to make stripes on.
- To adorn with narrow strips or braids of some decorative material.
- That with which something is laced.
- The tied or threaded laces that form a netlike pattern.
- A beating as punishment; a hiding.
- Lagging, or cross-pieces placed to prevent ore from falling into a passage.
- The cords by which the boards of a book are fastened to the back.
- The knee of the head, or lace-piece, a piece of compass or knee timber secured to the back of the figurehead.