But before we get into this, please be warned that injury can occur if the following procedures are not carried out VERY carefully and that I can not be held responsible for any injury's that may occur.
OK. Find yourself a suitable bottle. Wine bottles can work very well.
Decide whether you want a straight slide or curved, which finger you prefer to use and choose your bottle.
Obtain, borrow or buy a glass cutter.
At this point you will need to decide if you wish to keep the lip of the bottle. It's a personal choice really.
If you don't want the lip, scribe a continuous line around the bottle just below the lip and again further down the neck depending on how long you want the slide to be.
If you want to keep the lip just scribe the line around the bottle neck at the length you require.
Now using a heavy nail with a large head tap gently around the scribed line from INSIDE the bottle.
If you don't want the lip do that line first.
You should find that the lip and or neck breaks of clean at the scribed line.
NOW THIS IS WHERE YOU MUST BE VERY CAREFUL
The sheared edges will be VERY sharp.
Using a piece of Emery Cloth carefully rub the sharp edges smooth.
You are now the proud owner of your very own custom made Bottle Neck Slide.
OK. So it might take some practice and several attempts to get it right but it can be done.
Just be careful.