I tried it out in an experimental capacity and found that it does work quite well. The hand held pump was a bit more expensive than indicated I think I spent $35.00 but that is still a great deal cheaper than one of those food saver things. I went to about 18 inHg vac and the lid was on super tight with a very refreshing sigh when opened.
The pump comes with a number of attachments, two hoses and a couple of splits so I guess you could do 2 jars at a time. The cone shaped attachment fit right in the food saver jar accessories. I just held it down finger tight until a vacuum was formed. Then I pumped it up to about 18 in I was going for 20 but stopped shy as I seemed to have reached a plateau. Having done so, I stopped and went off to listen to some Meat Puppets. http://listen.grooveshark.com/#/s/Plateau/1pmteB
I am a newbie myself, but even I know that this method is only good for fungi that are already dried if not dried and powdered!