Need to destroy Mesh and Material to avoid leaks in Unity?

I’m writing a game in Unity with programmatically created simple GameObjects (colored cubes), which each have their own Material and Mesh and may also have child GameObjects. I have found that I have memory leaks for Mesh and Material whenever a cube is removed. So I have developed the method below which does fix the problem.

But is this sensible? What do other people do? And are there any other GameObject Components I should worry about that may also cause leaks.

private static void DestroyGameObject(GameObject gameObject)
{
    int numberOfChildren = gameObject.transform.childCount;
    for (int index = 0; index < numberOfChildren; index++)
    {
        GameObject child = gameObject.transform.GetChild(index).gameObject;
        CubeWallView.DestroyGameObject(child); // Recursive
    }
    //
    Renderer renderer = gameObject.GetComponent<Renderer>();
    if (renderer != null)
    {
        Material[] materials = renderer.sharedMaterials;
        if (materials != null)
        {
            foreach (Material material in materials)
            {
                UnityEngine.Object.Destroy(material);
            }
        }
    }
    //
    MeshFilter meshFilter = gameObject.GetComponent<MeshFilter>();
    if (meshFilter != null)
    {
        Mesh mesh = meshFilter.sharedMesh;
        if (mesh != null)
        {
            UnityEngine.Object.Destroy(mesh);
        }
    }
    //
    UnityEngine.Object.Destroy(gameObject);
}