It appears that this product is methyl cellulose dissolved in water.
It has many uses, including wallpaper paste, laxatives, making large
quantities of cheap slime for movie effects (Ghostbusters, Alien,
Terminator, Star Wars III).

It is both a glue remover _and_ a weak glue that can be readily
removed with water for art restorations.  The bookbinding trade has
used it for removal of glue on book spines without damaging the sewn
paper book signature.

It tends to absorb lots of water, so its use as glue remover may be
to adhere and provide moisture to the glue itself without soaking the
wooden work-piece or book binding.  It also shows up in toothpaste, hair
products as well as medical lubricants ("Please bend over, Sir, for
this part of your exam!").  A nice Wiki on the substance is at

  http://en.wikipedia.org/wiki/Methyl_cellulose 

Ordinary cellulose wallpaper paste without massive plastic additives
would be a cheap source.  It is non-toxic, not digestible and not an
allergen.  Take care when mixing any powder to avoid breathing any into
your lungs.  It's an interesting product and I may use it when I am
cleaning glue off a pneumatic deck board.  It apparently has minimal
creep, so not so useful for freeing glue joints but good for cleaning
up the remaining glue.  Sounds like a lot less effort and mess than
sandpaper.

Thanks to those who brought this to our attention.

William C. Jensen-Frisk