You can make a lot of things with yarn from plastic bags (plarn), amongst others plastic bag sponges :)
By the way, I’ve presented before the shape of the sponge.
Links:
Plastic Bag Sponges (Trauku mazgājamā švammīte -soli pa solim.A SPONGE for dishwashing-DIY) (English and Latvian)
via: DIY: Plastic bags into dishwashing sponge
Here at unikatissima:
Entries with the tag ‘plarn’
TED Talk: Nature, Crochet and Geometry