Been here for a long time now and haven't contributed any so I guess it's about time to try.
The Steam Tonk Bug, there are several threads here and alot of other forums, people tell you how to do it but they don't explain the mechanics of it.
I believe I'm starting to understand it so I'll try to explain it to you.
Disclaimer:
Before you read this I assume you know the basics of the bug itself so I'm not gonna get too deep into that.
Explanation.
Using your Steam Tonk, then casting a spell will give you the 3 second stun debuff. The spell you choose to cast will be casted in the background, you will have like a hidden Castbar.
After the stun if the spellcast is long enough you go with a new cast, when your Previous cast reaches its end your current cast will shoot and the current cast's castbar will become the castbar running in the background.
When you then cast the third cast, that cast will finish when the new castbar in the background finishes, and it keeps going like that.
Also each time you use your tonk again, if you have been spamming your casts for long enough you gain a new 'hidden' castbar.
An Example:
I'll go on my mage, and I'll use Pyroblast after the tonk, then spam fireballs untalented.
So I go, Tonk, Pyro - This gives me the 3 second stun
When the stun is over I have 3 seconds to cast a new spell that is longer than 3 seconds. Because I have a 3.5 sec Fireball the spell will fire after 3.0 seconds.
Now I'll only have 0.5 sec left on my Fireballs castbar, I use fireball and It goes off in 0.5 seconds.
My next cast will then go off in 3 seconds, if I choose wait 2 seconds it will fire in 1 .0 second. Then 2.5 secand so on.
If you however wait too long and your 'hidden' castbar runs out the bug goes away.
Summarized
To sum this up, imagine yourself having 2 castbars going on at the same time, when your hidden castbar finishes your 'hidden' castbar will make it fire, then your second cast will fire off what was your current castbar.
Also if you're not a mage, or just dont have these long casts (3.0+ or more) I suggest making a macro including your pvp trinket.
Code:
/use Steam Tonk Controller
/cast *Spell*
/use 13/Insignia of the Horde/Alliance
Personally I prefer pressing the pvp trinket myself since you will have a global cooldown on spell after the tonk spell anyway.
Also if your cast is too short the global cooldown will probably mess your two castbars up.
Guess it's better to try and contribute rather than not doing it at all.
//Lucyon