Yes.
Without a doubt. There are no laws governing the use or ownership of alcohol breathalyzers.
But you may want to consider the following: Breathalyzers are not meant to be used to "maximize" the amount of alcohol you consume before you drive. Any alcohol that is consumed before driving will impair your reflexes, judgment and ability to react to different driving situations. That being said, there is a time that alcohol breathalyzers should be used.
Every night drivers stand by their vehicle's door asking themselves the same question, "Am I alright to drive?". They "feel" okay, have only had a few drinks and already planned to drive home after drinking. So what do they do? They guess. Sometimes right, but often wrong. Studies have shown the impairment begins once a person's blood alcohol content (BAC) is above 0.05%. But how are you supposed to know? You feel surefooted, you are not slurring your words and don't exhibit any outward signs of being intoxicated.
The question is, are you impaired?
There are only two scenarios that play out at this point; call a cab/friend for a ride or drive yourself. Unfortunately, most people that don't feel impaired rationalize that they are okay to drive - while legally impaired.
So here is an option to scenario two. If you have the clarity of mind to rationalize driving then surely you can test yourself first to confirm it. It takes only a few seconds to test your breath for alcohol and it could save your life, some other driver's life or at least save you from costly legal ramifications.
Use a quality, calibrated alcohol breathalyzer like the BACTRACK® B70 - Personal Alcohol Breathalyzer and test yourself before you drive. It may save your life.