The smell of cyanide in the morning

I needed the terrace cleaned. The good old things like hot vinegar, some chemical shit to remove calcareous deposits and copious amounts of scrubbing didn't help much so I got a bottle of industrial strenght something. It had all sorts of warnings (corrosive, will tear your heart and drink your blood, use respirator and hazmat suit etc.) and when poured on the crap, it reacted, producing a lot of foam and something relatively easy to scrub off. It kept dissolving sponges and brushes, too. While smelling of bitter almonds. I don't really know why, for goodness' sake, on perfumes, you get all the linalools and citronellals, which may be and often are constituents of natural oils, and on various household and chemical plant products say Less than five percent of non-ionogenic tenzides; acid. I want to know what caused the bitter almond smell, was it hydrocyanic acid or some smell-alike? I couldn't have enough of that smell, it was beautiful, weren't it for another acid smell, good old vinegar, or, to be exact, concentrated acetic acid, which came along. They could keep the acetic acid for themselves but I'd love to have a bottle of bitter almonds. Terrace cleaned, new gunk may build up.