"Bocsi" is accepted - I just tried it. Otherwise, I commonly use "Bocsánat", "Bocs" and "Bocsi" when in Hungary depending on the level of formality I wish to convey (eg. the position of the colleague I am talking to.)
I've had frequent assignments in Hungary through work and can confirm that - as surprising and as it sounds - the expression "Háló!" as well as the expression "Szia!" are both commonly used for both meetings and partings, therefore for both "Hi!" and "Bye!"