Vinegar is considered to be a safe cleaning agent when it comes to cleaning vinyl fences. It is an acidic substance, so it can help to remove any dirt or grime that has built up on the fence. However, it is important to dilute the vinegar with water before using it and to test it on a small area first to make sure it does not damage the vinyl. Additionally, it is important to rinse the fence thoroughly with water after using vinegar to remove any remaining residue.