in blog post comments bad word not applying.

If you are checking in code behind, See example code below, which works fine as custom code.

var textToSave = XCMFunctions.ProcessCheckAllBadWords(textToCheck);

 public static string ProcessCheckAllBadWords(string textstring)
    {
        // Hashtable that will contain found bad words
        Hashtable foundWords = new Hashtable();

        // Modify the string according to found bad words and return which action should be performed
        BadWordActionEnum action = BadWordInfoProvider.CheckAllBadWords(null, SiteContext.CurrentSiteName, ref textstring, foundWords);

        if (foundWords.Count != 0)
        {
            switch (action)
            {
                case BadWordActionEnum.Deny:
                    // Some additional actions performed here ...
                    break;

                case BadWordActionEnum.RequestModeration:
                    // Some additional actions performed here ...
                    break;

                case BadWordActionEnum.Remove:
                    // Some additional actions performed here ...
                    break;

                case BadWordActionEnum.Replace:
                    // Some additional actions performed here ...
                    break;

                case BadWordActionEnum.ReportAbuse:
                    // Some additional actions performed here ...
                    break;

                case BadWordActionEnum.None:
                    // Some additional actions performed here ...
                    break;
            }

            return textstring;
        }

        return textstring;
    }