Rising GBH can get higher, but lower with one? (5-3)

I believe the answer is:

punch-bag

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'lower with one?' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'rising gbh can get higher' is the wordplay.
'rising' becomes 'pu' (I can't justify this - if you can you should believe this answer much more).
'get higher' indicates anagramming the letters (I've seen 'gets high' mean this (high can mean drunk)).
'gbh'+'can'='gbhcan'
'gbhcan' with letters rearranged gives 'nchbag'.
'pu'+'nchbag'='PUNCH-BAG'

'but' is the link.

Can you help me to learn more?

I've seen this clue in The Telegraph.

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