Did it work?
It was clearly not silly because Lincoln didn't think it was silly.
Did it work?
It was clearly insufficient to convince the seceded states that they should remain in the Union.
Apparently they either believed it wouldn't happen, it wouldn't be effective, or it simply wasn't what they really wanted.
Considering direct trade with Europe would have moved 200 Million dollars per year in trade out of the hands of New York and Washington DC and into their own hands, I'm suspecting that this was what they were really after.
Always follow the money.