Google search results for me turn up ~4k hits for "acorn away", vs. nearly a million for "squirrel away".
Similarly on Google Ngram Viewer: <https://books.google.com/ngrams/graph?content=acorn+away%2Cs...>
Though "acorn away" seems to have had some currency in the mid 19th century:
<https://books.google.com/ngrams/graph?content=acorn+away%2Cs...>
Though not in the sense you are using it best I can tell.
"Squirrel away" seems to have gained in prevalence after the 1950s, for some reason.
Google search results for me turn up ~4k hits for "acorn away", vs. nearly a million for "squirrel away".
Similarly on Google Ngram Viewer: <https://books.google.com/ngrams/graph?content=acorn+away%2Cs...>
Though "acorn away" seems to have had some currency in the mid 19th century:
<https://books.google.com/ngrams/graph?content=acorn+away%2Cs...>
Though not in the sense you are using it best I can tell.
"Squirrel away" seems to have gained in prevalence after the 1950s, for some reason.