The "Final Solution" was not declared in the 1920's.
Private diary entries of Nazi propagandist expert Joseph Goebbels and Himmler show Hitler ordered the mass extermination of the Jews two weeks after his first meeting with al-Husseini. The order was given on December 12, 1941. Goebel's entry reads:
"...with regards to the Jewish Question, the Fuehrer decided to make a clean sweep."
That stuff was written in the 1920s.