How do you maximize alcohol effectiveness and minimize hangover?

I was listening to a podcast of a Russian doctor the other day and heard an interesting theory that he presented about drinking alcohol but can’t tell if this is bs or not. Essentially, instead of taking shots, he recommends sipping hard liquor very slowly thereby causing max absorption through the sublingual mucosa. This will allegedly cause better absorption into the blood stream and will require less alcohol to reach the desired effect, which will result in less acetaldehyde which causes the hangover. He also recommended drinking a small amount of alcohol about 40 minutes before a party to activate the liver enzymes. Also, consumption of lemon during the drinking event will allegedly assist with hangovers. He swore by this method to not wake up with a hangover. Is there any scientific merit to this?