From Derek Lowe:
Neither you nor the mixer will be improved by the HF, which is one of the last things on earth you would want to expose such equipment to, and then there’s the matter of handling the Sarin itself. These process problems have been apparent since the German efforts to scale up nerve agent production during the Second World War, and a good deal of work in the 1950s and 1960s went into figuring out how to avoid them. You do not avoid them with the rig shown at the Russian theme park. It would kill everyone involved, and the only question is which awful thing would happen first.
Propaganda has a fatal weakness. It depends on ignorance and a lack of inquisitiveness.