Sorry to add another writeup to this already bloated node, but Flash is also a range of cleaning products for bathrooms and kitchens. Produced by Proctor and Gamble and sold in the UK (and probably other countries), its TV advertising campaigns largely consist of a husband buttering up his wife by offering to do all of the kitchen and/or bathroom scrubbing and cleaning for her, and then using Flash, which obviously takes very little time and effort. The slogan is "Flash (insert type of cleaner here) does the hard work, so you don't have to."
Flash is also the name of the title song to to famous bad sf film, Flash Gordon. It was written by Brian May and performed by Queen, and includes some voice samples from the film. I would include lyrics but they are already provided at the Flash Gordon node.