Or go green, or leave it in mega bad condition, don't do it, if you want sun streak i've used the john freida blonde sun streaks gel (yellow tube), but only use if you've got blondeish hair already if you put it on brown hair you'll go ginge. better still go to the hairdressers and pay to get it done properly...
Don't know about the vodka bit but we used to do ours with lemon juice when we were kids. Never seemed to cause any problems except trying to keeps the wasps away was a pain !!
haha, you'd be better off using sun- in. if your set on doing it, more lemon than vodka, but do be warned, it makes your hair weak, and brake, and worst case - fall out!