I do the DH project every month and have tried several mons; some good, some just difficult overall to use. Gimmicky sets can catch people off guard. So, the question comes down to whether straying from the more established mons or sets viable.
The answer is yes, but this different set must be able to do something that wont be able to just catch people off guard.
For example, Emboar is a much less used mon. Reckless is a big boon to the power output for this piggie. Now, a mixed set is very viable since it has the tools to do it (high hp, FB, Wild charge, grass knot, sucker punch, etc..). So, it can tear things up pretty easily while differentiating it from Infernape which can go mixed, but lacks the priority to beat faster psychics like Azelf, Alakazam, Starmie, etc..
Now, a gimmicky set would be Scarf Emboar. It would catch some.people off guard netting a key KO when they were expecting to survive, which could net them the win. But, put those battlers again and its almost guaranteed they wont make that mistake again. The first set has more viability in the current meta despite emboars low usage moreso than scarf which loses its viability once the surprise is up.
If ypu want a more relevant threat that probably shouldnt be played is Scarf Crobat. Once the gimmick is up, its easy to check, but when the time comes it can catch a player off guard. I had a battle the other day where i managed to pass +4 sp atk boost to Yanmega. At +1 speed it shouldve been able to beat pretty much everything including non scarf bat. But, the opponent had that and i lost that match sadly.
Edit: but regarding Scrafty, i think the meta is too fast and hard hitting. you have faster and stronger dark types in Mega Absol and Hydre, faster fithting types in Infernape, Lucario, Mienshao and Cobalion (id argue cobalion is probably the closest one to truly outclass scrafty due to higher hp and def and ability to boost attack faster in SD). Thrn we have straight up more powerful fighting mons that dont need to boost; Machamp, Pangoro, heck even AV Hariyama can have a better niche than Scrafty thanks to Thick Fat and huge HP.
I tried Scrafty. Its BU sets are ruined by Fairies which easily ohko even from a coverage move in dazzling gleam from a non fairy. Its dd sets are too slow where crobat outspeeds +2 and easily ohko. I think it has to be at +3 for even to be faster than mega Aero, beedrill scept, pidgeot, etc.. ifyou run jolly thrn the power output is even less and bulky mons can phaze with roar or be able to take the boosted hit.