I submitted a disavow file on March 26, 2013 and the disavowed links were removed. It is now August 12, 2013. I submitted a .txt file with the list of links one per line. I have read that you have to fist contact all the webmasters with the bad links before submitting. I did not do as such, I just submitted a list. I downloaded the list of links on Excel removed the links I wanted to keep and copied the rest and pasted them on Notepad. I saved the file and uploaded and they were removed, it took less than 4 1/2 months.