Situational at best, most stuff that get trough Gallade are either using priority or Scarfers.The destiny bond set possibly can be more functional than the standard sets because M-Gallade reaches 350 speed, it's high, after defeating a mon w/ Close Combat your defs goes down and you can got 2 kills on mons that are slower than M-Gallade.
The Stall sets it's a little bit crazy from my part, i just wanted to explore the Taunt/W-O-W on Gallade, it's not all this bad tbh, he reach 256 spe without any EVs, W-O-W + Def EVs allows gallade to hold a lot of Physical Sweepers, Drain Punch gives you durability and Knock Off doesn't need explanation.
I'm not telling that those sets are better than the standard ones, i just wanted to make them and share them here.
I'm not a fan of bulky Gallade, in 4th Gen it was good and had a niche in OU, on the 5th gen it got shaky but could be a surprise winning condition breaking trough weather teams lacking tornadus yet as of now you should consider Taunt CC 2 attacks or SD CC/DP(You actually lose some matchups with DP despite healing you) +2 attacks the most reliable ways of using mgallade in OU.