Bette

It's possible that Reggie is in better touch with his swallowing ability than his doctor. My Speech Language pathologist (SLP) who also did swallowing therapy told me that many of her patients were only comfortable at first with water. They knew that although it was not apparent that they were aspirating a little and water is the most innocuous drink possible. Once the SLP had done a modified barium swallow test (which requires a doctor's prescription) that showed the mild aspiration, she worked with them to add other liquids.
If nothing else, getting that doctor to prescribe SLP sessions and a MBS may yield the best results in getting Reggie back to normal. A good SLP knows how to motivate and help people start swallowing normally and has seen all the issues.
Just my two cents
Charm