Would it work and is the hashing rate be similar to the advertised hashing rate?
yes it would work, but it is not profitable, it is more like a gimmick to see how it works. With 5 Ghash you would get 0.6867 PPC annually at current difficulty
Where/what calculator are you using to get that number? I was planning on setting up an raspberry pi rig with 24 USB miners at first and then depending on profitability, setting up a few more rigs