Actually you never want to run the intensive bottle dry because when you accidentally activate the intensive system the pump will run dry damaging the impeller seal. If you decide not to run the concentrate solution I would advise using something like Prestone De-Icer in the winter time in both bottles and Prestone Bug-Wash in the spring and summer seasons.
You can purchase the concentrate for the Intensive bottle from either Amazon, WalMart or ECS Tuning look for (P21S). Mix the concentrate with your choice of washer solvent.