Tapping the joint on a hard surface can sometimes do the job.
Just be careful how hard you tap it
That could create hairline fractures in the carbon, which can get bigger over time and evetually lead to a break. You shouldn't tap rods off anything.
I'd try the two-man pull first but it should be noted that one person should remain absolutely still, allowing the other person to do the twisting. Doing it this way allows one person to have absolute control over how much torque is actually applied. Also, 2 people twisting at the same time may flex the blank a little which makes the jam even tighter still. Then you're both just fighting each other.
You can also make a grip on either side of the joint with elastic bands, creating an X-weave type affair, which gives you and the rod something to act upon.
WD40 works alright as does GT85. I would go for the latter of the two since it contains silicone, which is more slippery than a slippery thing. Great for regular lubricating of reels too I might add...must be regular though.
Once you have the two joints apart, I'd rub the male end with a soft pencil, like a 2B. The graphite fills any little imperfections which can trap grime or moisture, both of which can glue a joint together AND it also makes an excellent lubricant.