As I said in the OP I tried all of the "standard" options: stance+block+down, down+block, stance+block, dwon+stance+3 and probably a bunch more and I still son't know how to do it, some additional requirements maybe? or different inputs?
On a side note: punchwalk brutality requires 2 bars after final patch which is not simple to have with Goro, oh well, the one with the stomp is still the best in the game