For me, the best way of getting rid off the corruption or greatly reduce it at least is by filtering the government itself. Hunting down the corrupt officials is the key since they are the root of the problem because I believe that clean governance is the start for continuous growth.
Even we hunt them and remove from their position, corruption won't end that easy. A blood that runs into the system that can't be stop unless you kill it. And achieving a clean governance is like finding a salt in water. Impossible.
So this blockchain technology that OP wanted to do in government is insoluble and I guess government won't agree to establish a decentralized thus they want it to be fully centralized wherein they can manipulate everything. And many aspect should be taking out for consideration but one thing is certain that having blockchain isn't the answer.