Sometimes I wonder if it's worth explaining the semantic legerdemain upon which the equivocation rests.
"Abstain" in English is an intransitive verb. It cannot take a direct object and neither can it transfer action between subject and object.
It's true that in casual conversation, we might use the word, "abstain" in connection with a physical thing, but we don't do it unless a finite verb is clearly understood from the context.
Consider these two simple examples:
"Her obstetrician said, 'Pregnant women should abstain from alcohol.'"
"His dermatologist said, 'Persons with sensitive skin should abstain from alcohol.'"
Even though both doctors have told their patients to abstain from alcohol, they are clearly not talking about the same thing. In the context of pregnancy, it would be understood that the obstetrician was referring to alcoholic beverages. In the context of sensitive skin, it would be understood that the dermatologist was referring to topical preparations containing alcohol.
There is no reason why a person with sensitive skin could not drink an alcoholic beverage and there is no reason why a pregnant women could not apply a perfume or other cosmetic containing alcohol to her skin. The context of the, "Abstain from..." statement clearly determines the scope of the prohibition.
Similarly, the Apostolic Decree had a very clear context. It was the end result of a debate over whether Gentile converts to Christianity should be compelled to follow the Law. Therefore the eating of blood as forbidden in the Law is the context of the phrase, "Keep abstaining....from blood."
So there are multiple levels of dishonesty in the JW analogy between blood and alcohol. Not only are they making an invalid comparison, they are invoking a partial predicate (i.e. Abstain...from blood) apart from the context that completes it for the express purpose of misleading the audience into believing that biblical prohibitions against eating blood are stated in terms broad enough to include transfusion.