I use a crate and so far so good with Bella. She used to bark and whine when I walked away but I would leave her 5 mins and reward her if she was settled and let her out, I increased this time until it was 30 mins without her whining for me.

I also put her in the crate the first time I got the hoover out as I didnt want her to a) be afraid and b) attack it. Now as soon as I get the hoover out she takes herself to the crate and just lays there watching me until Im done and she comes straight out-she isnt scared of it just knows once its done she gets played with.