[CHDchest]

I used an asthma spacer for the domes. Basically, they can be taken apart into two pieces for cleaning, and I used one half each as a dome.

There is a picture of a child using an asthma spacer on this page:
http://www.asthmafoundation.org.au/Spacers.aspx

I put packing tape around the edges to make a tight seal and to stop the edges from digging into me.

Then I used some tubing about 3/4 inch in diameter and poked it into the end of the spacer (where your mouth or the inhaler would go) and taped it in place, making sure to seal it off properly. I did this for both halves of the spacer.

I used tubing like the one from my cliniflo (picture on this website):
http://www.smiths-medical.com/catalog/lung-expansion/insentive-spirometer/cliniflo-flow-based-incentive.html

I taped the two ends of the tubing together so I could use both domes at the same time, and pushed the whole lot into the end of a vacuum cleaner. I ran the vacuum cleaner on the lowest setting with the domes on my chest.

It seemed to work - I was getting sucked into the 'domes' and turning a little red, like what happens with the noogleberry, but it was very cumbersome and also required the use of power. The asthma spacer was only about 10cm in diameter as well.

So in short, I guess it worked but for the cost of running power and the annoyance of not really being able to move while using it, a device specifically designed for the purpose is probably better.