Refining Aid Question

Contradicted - Sanctuary

I saw somewhere that when refining without any aid's it has a 40% chance to succeed whether your going from (+0 to +1) or (+11 to +12), i dunno if this is true or not confirmation would be nice. But my question is about Tienkang Stones and Tisha Stones, if you forgot which one does which its as follows:

Tienkang Stones
Greatly improves refining chance
Tisha Stones
Increases refining chance
Refining level will only drop by 1 if refining fails

i wanted to know if anyone knows the precise amount each stone increases refining by, i apologize if this has been answered somewhere already but i fail to find any type of answer =(

please dont say: omg those stones are lame dont even bother just use Dragon orbs!!!1
these stones have been sitting in my inventory since the tideborn quests and i think ima use them to refine a Cape Of Tauren Chieftain

i greatly appreciate any comments made.

Brigid - Harshlands

I think there's some kind of table of percentages that shows up in the Auction House if you mouseover the filter for Refining Aids. Other than that though, I dunno. You may also want to read through the "Refining for Cheap" thread in General Discussion.

Contradicted - Sanctuary

i believe the table your refering to is the table for Chienkun Stones it shows the % chance that it has to stop the refining level from droping if refining fails
and the chances are simply appualing o.o when refining to lvl 5 and past it has less then 1% chance to stop it from dropping whats the point in using them? lol