I won't go into how often I went to the pictures but I will mention something that happened in almost every performance I sat through. In the interval, usherettes would walk up the aisles with their Flit guns, covering everyone in a sickly flowery spray. It was bad news if you were sitting next to the aisle as there was a very high probability of getting enveloped in a cloud of vapour that covered everything - ice cream, crisps, your body...The formulation used contained, in addition to some perfume, 5% DDT, at least until the mid to late 1950s, when the negative environmental impact of DDT became more widely understood and its use was phased out to be replaced with a 'normal' disinfectant.
Why was it done? Two reasons: firstly, to combat any unwanted creatures such as fleas and other pests (why do you think old picture houses were also known as 'flea pits'?) and secondly, to get over the odours of the auditorium. Think about it: a confined space packed with smoking clients who probably only bathed on a weekly basis, the pictures would not have been a place for lovers of fresh air.
And the Flit gun? It was an adaption of the traditional garden spray and pumping the handle blew out an aerosol containing the insecticide dust.
This practice certainly wasn't unique to the Workmen's Hall (although Mrs P never came across it in the Palace Cinema in Risca just 7 miles over the mountain) and it was commonplace right across the UK. Linked, or so it would seem, by the fact that the cinemas were located in working class areas. I don't know when it ended but it was going on locally into the early 1960s but after that, I can't say. Looking back, it does seem to be a very strange piece of sociological history but is probably still happening around the world. Thinking about it, I have been on flights where the plane, and its contents, have been sprayed with something similar. Plus ca change.