3 Answers

• This is code I wrote to get all the cookies from a webView.

  var webView = Ti.UI.createWebView({url:"http://www.google.com"});
  win1.add(webView);
  
  webView.addEventListener('load',function(e)
  {
      var cookies = webView.evalJS("document.cookie").split(";"); 
      Ti.API.info( "# of cookies -> " + cookies.length  );
      for (i = 0; i <= cookies.length - 1; i++) {
              Ti.API.info( "cookie -> " + cookies[i] );
      }
  });
  

  You could modify it to get the cookie name as it loops through and then delete the cookie like this

  webView.evalJS("document.cookie = cookie_name += "=; expires=-1";");
  

• you can like this

  Ti.Network.createHTTPClient().clearCookies('https://url_to_clear_cookies_for');

  even if using webView.
  it will works

• You could make a function inside the html of the WebView, that cleans the cookies.

  If you need the cleaning to be done only once you could trigger this function with a Titanium event, only when the app starts.