I know there have been whole threads dedicated to interpreting the negative meanings of spit -- OMT's spitting as well as all the times Jack or Ennis spits during a conversation to express anger or contempt or dismissal. But I've never considered analyzing spit in the positive sense.
Well, it's not necessarily positive. There's a difference between swapping spit and spitting.
For instance, one is not typically suffused with a sense of pleasure after dreams involving spitting, whereas dreams about swapping spit...
But, you know, spitting into a CUP, as opposed to swapping spit on the lip of a bottle...
I'll say this, though, if it turns out that Ang plotted out the saliva symbolism so carefully that it included the spit string, I will gain a whole new level of admiration for his genius.
Actually, he planned it all out carefully, every bit of it, to drive us all completely bonkers.
I'm sending the man my therapy bill.