Arknok, I think he meant max 9 tries, because every extra try for the same extended test takes place at a cumulative -1 penalty. If you take a look at what I rolled, I started with 6d6 the first hour 5d6 the second, etc. etc.
Thus with 10 dice it's a maximum of 9 tries, although I would advise you to stop around a 4 dice pool to avoid critcal glitches that kill the entire effort.