The contents of the temporary table in oracle are displayed only for the current session or current transaction.
Therefore, they are ideal for temporary data. Don't worry that other users see (and confuse) the data. No need to explicitly clean after you.
In addition, you do not generate REDO for the temporary table, since 9eg will never be used for recovery). As such, they can be faster.
(if you run this answer, please add a gary comment since I just copied it into the answer)