I've grown up in a rural area, and while I associate dav/davs with old farmers or workers, I rarely hear them use it nowadays.

I occasionally use "davs" semi-ironically but it is definitely not the most common greeting. It's probably not a greeting you should use the first time you meet someone, or at a job interview, but it is fine (albeit a bit atypical) for greeting friends. Hej or hey are more common, and as a bonus, also much easier to pronounce for the average English speaker.