OSLF,
My father didn't say where the spraying took place, or if he did I cannot remember. The squadron was there for exercises and thought it appropriate to attack at an unexpected time, such as the Special Bull Parade in question. He said the tanks were about the size of 40gl oil drums and were held on underwing racks. That's all I know about Montrose.
Another story which may be apochryphal, yet contains some believable items:
In 1942 many runways were still being laid or lengthened to handle the four-engined fleets now rapidly increasing. With most young Britons conscripted, an army of Irish labourers crossed from neutral Ireland.
The work did not always run smoothly and the workers sometimes went on strike for more money, as indeed did the dockers. The aircrews, nightly risking their lives over Germany, were not in general agreement with these workers' rights. It was therefore rather unwise of a group of striking workers to inform a couple of crews that civil engineering was strenuous and deserved extra payment, while some had an easy life flying about in aeroplanes. It was even more unwise to express such views to Canadian aircrew.
As my father heard the story, the crews kidnapped the foreman and possibly one of his workmates as they left the pub that night and held them captive the next day, while their base was locked down before operations. The hapless foreman was taken to the Ruhr and, fortunately, back again. He did not enjoy his flight, still less the extra ventilation which appeared beside him, and of course raised a great commotion after he was dropped from a Hillman utility somewhere across the airfield.
The culprits did not return from operations a few days later, and the inquiry was quietly dropped. The story did not say if the airfield works were completed.