You're getting hosed. The transfer should take place face to face. You can't un-wire money. There is absolutely no reason for you to forward money until you see the appartment. Think about it. He will need to drive to meet you anyways to show you the apartment. What if you did not like it? There is no reason to give him money until you see it. Swiss law requires deposits to be held in an escrow acccount in a Swiss bank.

You're getting scammed big-time. Don't waste any more of your time.