At the moment I'm trying to lower my voice. I can hear improvements, but now I have pain in my throat everyday (at least since I started 5 days ago). I saw one video of Sinn where he was telling about speaking with a lower voice. He said he had a lot of pain in his throat from speaking with a lower and louder voice. He is saying that it is a normal side effect and every time you have that pain, your voice is getting stronger.

Does anybody know if he is right on this?

And I would also like to know if should let my voice rest, or continue with speaking while I'm having this pain?

My initial reaction is that he's wrong as it shouldn't be causing pain. I think you need to be lowering your voice by speaking from your chest. I may be wrong though!

Thanks skypirate. The pain I was having was not a problem, It only hurt a bit while speaking. The reason for that was that my vocal chords were swollen and with some voice exercises and drinking a lot of water the chords get back in it's normal position.
Now I'm used to it, I can speak without having the pain... even in clubs.