I should think you could find an Elmer's substitute in New Zealand. It would be the type of glue used in lower elementary school grades as it washes easily out of little hands, clothing, hair, etc. A teacher of young children would probably know exactly what glue meets these criteria! It's typically very inexpensive too, in part because all it consists of is a very thick starch.
This may be a source for you in NZ:
http://www.warehousestationery.co.nz...421019@WSL-B2C