I am 99.99% sure that failing does not use up the "special" ingredients: void orbs, demon claws etc.
As an aside, your weapon is somewhat contradictory to itself. For 1, if the main thing you want is HML, then you should be reforging HML, not imbuing it. But lets assume for some reason that copper hammers are beyond your reach.
Wanting both HML and SSI, on a katana, is pretty tough. Even with only 120-149 stamina, it only takes 5% SSI to swing your katana at the max speed. You can super easily get 5% SSI on a shield, and even with a stat cap of only 230, 140 stamina should be well within reach for someone who can imbue. If you put any reasonable amount of SSI on there, sure with 35 ssi on there you can swing it at 1.25s with only 60 stamina, but then your leeching will be somewhat limited.
You also have another inherent contradiction on that weapon. You want slayer AND hit spell. The thing of this is, that on the hits where the hit spell is invoked, you lose the slayer property. I think this is a bug, but it has been around for as long as hit spell on weapons has. So, lets say you have Hit Lightning on there, and this sword is an undead slayer. Lets also assume that you're using Consecrate Weapon, and that youd damage output is reasonably near the max. Against most 'normal' undead things you'll do 80-90 damage per hit. (50ish from your weapon damage as shown in status window, - their armor (low against fire) *2 for being a slayer). On the hits where you hit lightning, you'll do 45 damage from the weapon, plus maybe 20 damage from the spell hit. Not only that, but you don't get to leech anything from the damage done by the lightning, thereby further reducing the effficiency of the weapon. Now, against someone with no slayer... yeah, for sure, putting 100 hit spell on a weapon makes sense.