The most common and most likely answer to this crossword clue is the 8 letter word FRUGALLY
I've seen this crossword clue in The Daily Telegraph
F
R
U
G
A
L
L
Y
More clues leading to the result FRUGALLY
Buddy explains!
The straight part
We know that "Rag fully recycled — when one acts thus?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rag fully recycled — when one acts thus? = frugally.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.