If you dont want to save anything in SAP, then the best option to develop a form in Word or Excel to send it as attachment to an email to the approver, and after the approval you can enter it in SAP.
If you dont store anything in the database, then it is just gone if you close the transaction.
enter a value in Excel and close Excel without saving, or shut down your PC. The value is gone, how do you expect it differently?