Ask HN: Best substitute for compressed air can?

So I've been trying to keep my keyboard and workstation clean on a regular basis recently. Purchased a single can of compressed air for about $12 or something and it lasted maybe a week/two of dusting a keyboard like every other day. Not very long or at least not as long as was expected.

I don't have an air compressor (and that's also overkill for my needs) but are there alternatives to compressed air in a can? Am just looking to blow off dog hair and dust that settles on a computer etc.