As you are already aware, one of the methods of collecting unpaid rent after obtaining an order from the Board is by garnishment of wages. Of course this is only possible if you know where the tenant is employed. Another way is by garnishment of a bank account as long as you have all the information on where the tenant banks and where the tenant is residing now. However, if the tenant is not employed and is receiving any type of government assistance, it is pretty much impossible to collect since you cannot garnish any government payments. You could try talking to a collection agency but unfortunately there may not be a way for them to collect either if he is on ODSP.