Oh man, I got a chuckle out of this one.  For alcohol, any ethyl alcohol, to be effective it would have to be close to 40%.  Buzz city!

On more of a serious note.  What I have used over the years, unfortunately for your request, is chlorine.  

I do have comment that may be helpful.  The biggest mistake I have seen over the years on this forum and this topic is somehow people think microbial life is spontaneous.  Its not a miracle and water isn't the Virgin Mary.  If its sterile when stored water has no shelf life.  It'll stay sterile forever.  That said, getting completely sterile to begin with is easier said than done.  There are many factors such as spore boring anaerobic bacteria the most common.  That you keep down by keeping the dissolved oxygen levels up, periodic mixing usually shaking.  Still its important to know life, all life, is not spontaneous. We are not creating it in our water storage.  It either had to already be there or from a contamination source. Also keep in mind all life depends on a food source.  Bacteria doesn't live in a vacuum with nothing to feed on.   If you follow this then our storage life is very dependent on first starting water quality and second storage container quality.

Now all this said, I do know one method to accomplish this and you won't like it.  Its an industrial deminerializer system which purifies water down in the micromoh levels like used for boiler feed water in nuclear plants.  Its water so clean, it not only will not conduct measurable electricity and the water becomes a super solvent.  It not the demin system under your sink and a system like that is over $1 million dollars.

Now you know why chemicals are so popular.  

Still if you understand all of this, you can greatly increase your storage life.  

Hands down the best home storage method I ever did was actually a water bed.  Sorry I can't remember the exact plastic but it was that material that made me think of it.  Anyway, I shocked the water with non-scented bleach and then the jossling of the bed kept the O2 level up while remixing the CL.  The water smelled about like tap water when I was forced to use it during a hurricane in TX and because I have a microbiology background, when I plated the water, I got no measurable growth after years of storage.   Even though it was a good plastic, I got some polimer leaching but nowhere near a Vietnam era canteen after just one day in the field.  That was 300 gallons that really paid off.  

If you follow, its the methodology you go after not necessarily a water bed.  

TJ