[This post and the blog have been moved to: http://www.carloshelder.es/blog/the-best-cough-remedy/]
I want to write it in English because I want that as many people as possible know it!
After arriving to Poland with the Erasmus scholarship, I had cough for more than a week. I tried different medicines and teas with honey... Nothing.
But then, I remembered the old best solution: just cut an onion in more or less small pieces, and left it close your bed (it is not a spiritual stuff: you have to sleep in that bed!). That's all. Simple? Yeah.
Notice: your room will smell not very well the next day.., take a shower!