If you are really interested in teaching in a particular country, you might consider taking a vacation there. While you are there, you could check out teaching jobs. However, there are good reasons for applying from home.
If you apply from home you are in a better position to ask for reimbursement of your airfare – and a return ticket when you complete your contract. You can also ask for a ‘settling in’ allowance. Usually this is a one-shot payment to help you to buy necessities. It won’t be a huge amount but it will buy dishes, etc.
If you apply from within the country, schools will most likely consider you a ‘local hire’ and be reluctant to pay anything other than salary.
Another reason for applying from home is because one of the documents many schools are asking for now is a police certificate showing that you do not have a criminal record. This is easier to get while you are still at home.