You can use anointing oil (if you have any, not many do, unless your church makes its own healing/anointing oil). If you don't have any, you can use olive oil; even plain cooking oil will do if you don't have any olive oil. Remember, it's the prophetic act that has the power, not the substance you're using (holy water being another such substance).
Use that, just a dab on your fingers, to anoint the top, bottom, and sides of every outside door and window in your house, and you're reenacting the Passover