There is a common Arabic idiom, which literally translated says:
Soak it and drink its water
It can said about pretty much anything, to express a kind of contemptuous indifference.
For example, when Hassan Naseralah was informed Hezbollah had been included in the European Union's list of terrorist groups, he made a speech where he said "You can soak your list and drink its water".
It's similar to the English idiom "you can shove it up your a$$ for all I care", except in Arabic the phrase is formal, not vulgar.
Is there a formal, or at least non-vulgar, analogous idiom in English which expresses contemptuous indifference, belittlement, and scornful dismissal?