I don't understand how Blockchain will be able to prevent corruption. Since the transactions will be traceable, none of the parties will prefer doing such payments. They will find some loophole to avoid it.
If the government would enforce it properly then corruption would be greatly reduced because the transactions are traceable as what you mentioned. They will let their employees operate in a system with blockchain technology because they wouldn't be able to just easily delete it and then they cannot just change the information in it. It would be a great help in tracing the people behind those transactions so that they will know who are the accountable ones.
During an election, blockchain would be a great help so that there would be proper counting of votes and the people who are manning those voting machines would not be able to easily manipulate the vote counts since they can't change the information.