A few years back in a CIS country while flying intra country flights on a smallish A320, I was called the day before by company ops: "Hi. You will have a random alcohol check tomorrow morning". What a service
As for submitting a test to a police officer, no problems and if you have nothing to hide it only takes a few seconds really. However a company I once worked for informed that they can have someone in the office conduct a brethalyzer test. With that I have a problem. These instruments are not calibrated properly and can show interesting readings after eating fruit or spicy food. Try to explain that to some 22 year old with life experience of a banana when she tells you that you are pissed a skunk. Not personal experience but happened to a mate.