The most common and most likely answer to this crossword clue is the 12 letter word REGENERATIVE
I've seen this crossword clue in The Guardian
R
E
G
E
N
E
R
A
T
I
V
E
Buddy explains!

The straight part
We know that "Refreshing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case refreshing = regenerative.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 REGENERATIVE mean?
REGENERATIVE adjective- That serves to regenerate.
- Being a kind of circuit, much used in radio receivers, that allows an electronic signal to be amplified many times through a feedback loop.