Food before you drink can slow the passage of alcohol into your blood stream but it won’t help you beat a breathalyzer test. A breath alcohol tester does not "smell" alcohol on your breath the way an officer can. Masking the smell of alcohol with breath mints, onions, gum or anything else won’t change the alcohol content of your breath or the reading on a quality alcohol breath tester.

However...chewing gum can bring some residual fumes up from your stomach so although the gum won't affect the readings directly, its presence can cause falsely high readings if the gas comes up (similar to burping).

Coffee Helps Me Sober-up Faster and Lower My BAC - False

Coffee will not change your breath alcohol content (BAC). Only time will reduce your BAC.
 

Mouthwash & Breathspray will Fool a Breath Tester - True and False

Mouthwash and breath spray may mask the smell of alcohol on your breath, however using these substances just prior to a breath test may actually increase the BAC level you register. Mouthwash and breath sprays frequently contain alcohol and will leave residual alcohol in your mouth and on your breath for up to fifteen minutes after use. You are very likely to register a higher result if you use these products a few minutes prior to being breath tested. It is important to note here that obtaining an accurate alcohol test result requires two things: 1) an accurate instrument and 2) utilization of proper testing procedures.  That is why it is universally accepted that an accurate result requires waiting 15 minutes to take the breath sample after the tested subject has put anything into his her mouth.

Nyquil and other similar products do contain alcohol, just like beer, wine, and liquor.  As such, they can contribute to or cause inebriation if consumed in sufficient quantities.   Alcohol testing devices do not differentiate between types or brands of drinks; they merely provide an accurate indication of BAC.

I suffer from GERD (Gastro-esophageal reflux disease) - True

Burping is always a possible suspect for a false positive reading.  GERD causes the individual to burp repeatedly thereby greatly increasing the possibility that the reading was wrong.  However...if you want to go down this route with the OSMV, then it's imperative that you can give evidence that you did in fact burp or could feel the gas fumes in your mouth at the time of providing the test.

My Breathalyzer Test was Positive Because I'm a Diabetic - True and False

Quality fuel cell based breath testers such as the Alco-Sensor IV DWF (the old machine that police were using) and the Alco-Sensor FST (the new machine that the police use) are not affected by ketones, a class of chemicals often produced in the body of persons with diabetes. However, cheap immitation roadside devices (for example if you buy an app for your cell phone) use a semiconductor alcohol tester and can react to other substances in the breath besides alcohol resulting in false positives.

Pennies will Absorb Alcohol and Fool a Breathalyzer - False

A penny in your mouth or under your tongue will not change your level of intoxication or fool a quality breathalyzer. Pennies, nickels, dimes, quarters, etc. do not absorb or mask alcohol. As a matter of proper testing protocol, officers make sure you have no substances in your mouth before conducting a breath alcohol test. Finding loose change in your mouth is likely to raise suspicions that you have something to hide.

Perfume may contain alcohol but this evaporates from the skin and disappears within seconds or minutes. Additionally, since quality breath testers are closed loop, sealed systems where one breathes directly into the mouthpiece the amount of residual alcohol in the environment is basically not a factor as the device is sampling only lung air. This one is highly unlikely.

Cigarette Smoke will cause me to Fail - True and False

Cigarette smoke can reduce the life of a fuel cell in the Alco-Sensor thereby damaging it over time so it is not be to blown directly into  until at least 5 minutes have passed to eliminate the smoke.  However, this won't have any immediate effect on the breath readings; rather, cigarette smoke becomes relevant if the officer's machine becomes damaged from continued improper use in other cases.

If I Hold a 9 Volt Battery to My Tongue I can Fool the Breathalyzer - False

Not at all.