Word Interop spellchecking a document word by word is too slow
===

With the code below basically I'm checking a document word by word and separate the correct ones. I works, but too slow that I have to wait for more than 10 minutes for 40 thousand words. When I open the same document word checks it in a few seconds. What am I doing wrong?

    var application = new Application();
            application.Visible = false;
            Document document = application.Documents.Open("C:\\Users\\hrzafer\\Desktop\\spellcheck.docx");
            
            // Loop through all words in the document.
            int count = document.Words.Count;
            IList<string> corrects = new List<string>();
            for (int i = 1; i <= count; i++)
            {
                if (document.Words[i].SpellingErrors.Count == 0)
                {
                    string text = document.Words[i].Text;
                    corrects.Add(text);
                }
            }

            File.WriteAllLines("corrects.txt", corrects);
            application.Quit();