Alcohol is a drug, the only thing that will sober you up is the time it takes to dissipate the alcohol from your system. Vomiting will lesson the amount of alcohol in your stomach, so technically...
Bread is great for sobering you up, also drinking lots of water to flush the alcohol out of your body.
No.
the only thing that can sober a person is time...drinking coffee is only a myth
be sure they drink lots of water to remain hydrated but there is no way to "sober up" someone who is drunk other than give them time to sleep it off.