How long is a piece of string??? lol
Seriously, you are not dealing with much thickness here so if the outside is really dry, the inside is also likely to be.  Moisture from the inside would seep outwards.
If it is humid, you can have a problem and it might be a good idea to finish off the drying in an oven on a low heat for an hour or so.
Pulp, when dry, will certainly not be 'squishy'.  It may have a slight resilience, allowing you to dent it with a finger nail.  If you add ground chalk to your mix it can seem almost as hard as concrete when fully dry.

And you can feel that the weight gets lighter, too. 

But your high humidity can be a problem.  Just a suggestion:  if you have access to a wood or cardboard box and some heavier clear plastic, make a very simple solar dryer.  Have one side covered with the plastic that faces the sun, a row of holes along the top of at least two sides (to vent the moist air), and access from front or back.  The heat comes in through the clear plastic, warms the air around the object, the heat rises and exits the box through the holes near the top.

Just remember that when your piece is fully dried, you'll have to seal it right away, or it will re-absorb moisture and get damp and soft.

Sue