ass salaamu alaykum
BRO' DHUL...this hadeeth .."movin' the finger up and down" is da3eef min qism as-shaad!!...
shadda bihi "Zaaida Ibn Qudaama" wa khaalafa 13 min ar-ruwaah
but al-Albaany rahimahullah says it's saheeh!....but i go with the qawl of it being da3eef!! That's what my teachers and most of Ulamaah al-Yemen have come to a conclusion with and i agree with it too...
and the right way is to just keep your finger pointed upwards and straight, without any movement!!...i can't remember the hadeeth it's in though...if any1 can remember it than plz post it in..
wa alaykum ass salaam