I feel like looking at the idea of the technique itself, and where it came from.
Would Jashin really give a crap if his symbol was old or new? I believe a death god would just want death in his name, his name being represented by the technique user and the symbol.
This is a good point,
if one believes the Jashin technique actually comes from Jashin and isn't simply another jutsu. Based on the requirements of the ritual -- namely that a ritual is required -- one could state that this is indeed the case.
Now, as to whether or not a god literally known as "evil god" would require fresh blood?
An argument could be made either way; the quote above shows one argument. The counter-argument is that Hidan literally prays to his god before a fight, as mentioned by Cameloui. This indicates that Jashin, like most other gods, requires devout sacrifice -- it is, afterall, a sacrifice to Jashin that purportedly gives Hidan his immortality. One could argue that Jashin'd see the dried, chapped blood of a previous ritual similar to recycling a gift, and not recognize it until the ritual's re-drawn.
However, this entire argument is moot
because none of us can know for sure what Jashin would think except Jashin himself.
So, if the power for the ritual
does come from Jashin, as previously inferred, then we actually need to get the opinion of the man who's already canonically claimed himself to be Jashin. Unless anyone's arguing Nashley's having called Jashin himself, he needs to be brought into this discussion about whether a dried ritual would work on that account or not.
Onto the next point: Could the dried blood have coagulated, flaked over time?
Could it no longer have any chakra or spiritual significance? I think the lattermost is the point here.
Chakra is described in the wikia as, "the moulding of the physical energy (身体エネルギー, shintai enerugī) present in every cell of the body and the spiritual energy (精神エネルギー, seishin enerugī) gained from the mind."
Chakra is vital to every single jutsu or form of "magic" in the Naruto world. It is the source of our magical power -- and if Jashin himself doesn't fuel the power of the ritual, then chakra does; namely the chakra in the blood that composes the ritual.
It may be impossible for us to decide one way or another for sure about how perfectly the ritual would be preserved (it's stated as dust having gathered, as others have mentioned; yet also dried blood
can last in an undisturbed area for centuries. Dust, however, deems the area as at least slightly concerned) or not, but one can definitely judge that the chakra in the blood isn't there any longer; not after months and months, and certainly not with the amount in one's blood alone. Based on this, I'd argue that -- if the ritual isn't from Jashin's actual power but from Bocchiere's chakra -- then the ritual needs to be redone.
So, let's come to a decision here, then: what fuels the Jashinist rituals: Jashin himself, or the chakra that fuels practically everything else in this setting?
If it's the former
and if the Jashin of this world doesn't mind dried, old blood then I'd say that the attack has succeeded. If it's the former and the Jashin declines unfresh blood or it's the latter and the chakra in the blood has faded, then I'd say the attack has failed.
---
And if it
is deemed that Bocc's ritual doesn't kill Kamui, there are a few more things to keep in mind:
Just because it didn't kill Kamui doesn't mean that Bocc needs to repost. Bocc, in a new post and after recuperating, would need to make a new ritual, yes. But that doesn't mean that his current actions would or could be voided; he's done the ritual, he's snapped his own neck -- the question is whether or not the damage reflected onto Kamui.
And I confess that I didn't have time to read the entire post, but if it doesn't kill Kamui, will Bocc immediately know? If Kamui isn't in the area, I don't see any way for him to even tell. Without knowledge, Bocchiere might not even know that his ritual had failed.
I suppose this my input.
