List<string> myString = new List<string>();

private IEnumerator Print()
{
    while(true)
    {
        foreach(string bar in myString)
        {
            Debug.Log("printIt:" + bar);
            yield return new WaitForSeconds(2);
        }
        yield return null;
    }
}

void Start()
{
    myString.Add("fu");
    myString.Add("bar");
StartCoroutine("Print");

}