Sounds interesting, I may try this for a laugh. What's the drink they use? And any sort of vinegar will do?
Yes, it's just a litle bit. i dont remember well the proporsions they use.

I saw mention of Sagres in Tiago's post..... I like the Sagres beer they sell in Nando's (lovely peri-peri chicken from there) - is the beer named after there? Also, Super Bock beer is nice (again, found commonly in Nando's).
Sagres is first of all a village name, the name of the beer i don't know if was any connection but probably has.
Super Bock (beer) in my opinion is better then Sagres.