Hmm, that is... not what I was expecting, to say the least. I just cannot see why you wouldn't run Machamp instead; they're basically the same except Heracross is hella lot more stressful to use thanks to Stone Edge's somewhat unreliable accuracy and because 100% accurate Dynamic Punch > Close Combat imo. The only thing I see it really having over Champ is the ability to beat Espeon and Alakazam thanks to Pin Missile ( 99% of the time just 2 hits are enough) both of which are pretty common sash leads and that just demolish Machamp 1 on 1 thanks to the aforementioned Focus Sash that they're usually holding.
To be honest, though, this is not even that big of a deal. I'm just genuinely curious to know what are people doing with it because I've rarely even seen it in the ladder ( although I haven't played much, if at all, in the last couple of days—maybe it got more popular later on). So yup, I'd love to see those replays if you don't mind sharing.
It busts Sash'd Psychic mons, yes, but a lot of it is that Heracross is much faster (max Speed ScarfChamp hits about 105 base Speed; falling short of Gengar and such), Close Combat hits even harder than Dynamicpunch, and Guts is also a factor. AV Machamp is crushed under WoW, as is ScarfChamp. Lum Champ can eat a WoW, but only once, and loses the bulk of AV and the Speed of Scarf. Heracross, burning it only makes it angry, and a +1 Heracross is very difficult to stomach if you aren't a Granbull. Heracross also smashes down Machamp by virtue of superior Speed and defensive typing. :P
Scarf Heracross is also amusingly good against Rain teams. I ran it a lot in Doubles, but not in this competition yet. Very, very unsure if I want Champ or Hera though. They're both great.