I will try to acquire some solid information/proof on this subject via Google-Fu and the wayback machine in short order..
Currently, as has been started many times over, the One Hundred Blows proc on this Tranquil Staff is not acting like it did on Live. I've yet to see it stun a mob for any measurable portion of time while continuing to attack it after the proc. It almost seems like this proc is working exactly like "Whirl till you Hurl" (recently nerfed by breaking upon damage). Are these two effects sharing some code of some sort?
-Minor evidence of proc supposed to last 1-2 ticks (up to 12 seconds)
http://replay.web.archive.org/200302...tml?spell=1809
ZAM Description of One Hundred Blows
+Duration: 1 ticks @L1 to 2 ticks @L4
-Some more anecdotal evidence of peoples experience with One Hundred Blows proc, (ctrl+f, search proc)
http://replay.web.archive.org/200302....html?item=572
+"The DD part of the Proc always happens, the Stun though still not stun Unstunnable Mobs. The Consensus on Monkly Business seems to be that the Stun Lasts for 3 6 or 12 seconds, depending on the mob's level. If you Duel with it it tends to stun other toons for 12."
+"This thing hurts in pvp, when my druid was lvl 49 er so i had a lvl 53 monk beeting on me with this, he procced once then again about 6 seconds later, needless to say a druid stunned for 18seconds against a monk with a weapon ratio like this isnt good"
In my experience in getting smacked with it in a duel...I get proc'd on, get the "One Hundred Blows" debuff/proc icon on my buff window, and am able to freely move around and attack while it is still "active" in my buff window. I didn't notice a stun whatsoever. You are supposed to literally spin in place. Probably would have been a different story if I was mid-cast, but alas, merely interrupting spells wasn't the great thing about this item.