A vacuum? Seriously?
It's not a closed system so there's no pressure!
There has to be pressure to have a vaccum... the SAME amount of unburnt fuel is going to be between the intake and filter, boost bottle or not.
I haven't done a reed setup, but there's plenty of people who have and are doing them.
Here, take this test.
Get some small hose line, such as that which is in the boost kit.
Get a clear bottle and airtight ducttape it to the opening, so the only way in is through the tube.
Light a cigarette and blow the smoke right at the tube. Hard slow, soft, short fast, anything.
Let me know how much smoke you see traveling through the tube and into the bottle. That's how much fuel vapor is going into the boost bottle. Now, if the boost bottle was on the inside of a reed and the pressurized intake mani had nowhere to push the unburnt fuel, yes, it would help because there would be some pressure and a vacuum would be created, but its not that kind of setup, and if it WAS, it wouldn't be 10 bucks.
EDITADD:
If you don't like that test then try this.
You know the fish tank cleaner/drainer vaccum tube, right?
It works cause there is an open end on one side. Try putting your thumb over the top end and pumping water out.
Or this one.
Drain a gas tank with a garden hose - but don't suck to start the flow. Instead, make an airtight seal between the gas can and the hose. Now, without squeezing the gas can, magically make a vaccum to get any amount of fuel into the tank.
Last one, I promise.
Take an eyedropper, and stick it upside down in the dirt.
Take a 5gallon bucket and dump it as best you can right through the opening. Let me know how much water got inside.