Regardless of the reason for the spit Harry would still have to follow through with whatever that is for the signal to be sent back in time to cause the urge to drink. Otherwise it would be like Harry escaping from that locked classroom after Draco tortured him without then going back in time and sending the Professor to let him out.
Regardless of the reason for the spit Harry would still have to follow through with whatever that is for the signal to be sent back in time to cause the urge to drink. Otherwise it would be like Harry escaping from that locked classroom after Draco tortured him without then going back in time and sending the Professor to let him out.