The product was introduced in Finland this autumn under the brand name Lotus Flush & Go by the US-based paper company Georgia-Pacific.
"The inner roll is designed to dissolve in moving water," says Heidi Toivola, marketing director at the Finnish subsidiary of Georgia-Pacific. She explains that it is made of the same materials as the toilet paper itself: pulp and corn starch.
The product was singled out for the dubious honour by Finland's biggest nature magazine, Suomen Luonto, which is published by the Finnish Association for Nature Conservation.
The magazine notes that tossing the roll into one's sewage water system rather than into a cardboard recycling bin is wasteful.
Past winners: Leaf-blowers and fireworks
Mari Heinonen, production director at the Helsinki Region Environmental Services Authority, agrees that flushing is the wrong way to dispose of used products.
"The toilet bowl should not be the home's waste-sorting centre where the consumer stands to decide which waste items should be flushed down," says Heinonen.
For the past 12 years, Suomen Luonto has picked the most frivolous and environmentally-unfriendly consumer item each year, based on readers' suggestions. This year it received 229 nominations.
In recent years the 'award' has gone to fur apparel, fireworks, non-returnable bottles, imported bottled water, leaf-blowers and all-terrain vehicles.