Help me understand what might commonly be known as the cowl.. Is this the area below the wiper blades, including down to the heat blower motor area? How do I get good access to the cowl?
That is correct. I went through the heater box assembly on each side and was able to insert a flexible vacuum hose to suck everything out of there. My situation was a little different since the car was sitting in a garage for more than 50 years.