I make sure there is NO paper on the bottom (contact area) of the rudder. I ligthly sand the fuselage at the contact area (everything has 1 coat of dope at this point) and I presume the glue penetrates the paper to make the bond.
HOWEVER... I like the idea of "pin prick" the fuselage at the contact point, and will do that in the future.
That's why I like to read these posts!
Mitch