He continued to send stories to the Siam Rath in his distinctive writing style, which was a combination of journalism, and story-telling.

Many of the stories were about the street life of San Francisco which were developed in one of his best-selling book Lost in the Smell of Marijuana (published in 1969; Thai: หลงกลิ่นกัญชา), and later in On the Back of the Dog the Golden Sunlight (published in 1978; Thai: บนหลังหมาแดดสีทอง),[8] a title which referred to his travels on a Greyhound bus in California, and San Francisco.

On the Back of the Dog the Golden Sunlight was published in English in 2022 with the title The Man from Bangkok: San Francisco's Culture in the 60s.

He appeared in at least one English language film, Saigon: Year of the Cat, where he played the role of the Foreign Minister.

His writing has been described as Gonzo Journalism because Wongsawan will often inject himself into the story, remarks on his emotional responses to his subject, and does not have a pretense of objectivity.