Found a solution. Mind you, had nothing to do with Postman or Fiddler. This is what I mean by: my code doesn't work, I need code that does.
(but G-G, thanks for the effort and time. :-) )
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "DELETE";
request.ContentType = "application/json";
request.Accept = "application/json";
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(data);
streamWriter.Flush();
}
using (var httpResponse = (HttpWebResponse)request.GetResponse()) { message = httpResponse.StatusCode.ToString(); }