They are ment to be casted on light tackle or behind a bombarda float. Casting all sorts of spinning/rolling L-shaped worms, dough etc. has a bit of a tradition here. The bombarda float is named "spirolino" over here, both terms indicating that the technique was developed in Italy for small ponds in fishing parks. This film might give you an imagination, lot of German talk at the beginning but also graphik display in the second half. Note the use of the word "twister", derived from the brand "Mister Twister", as a synonym for grubs!
[video=youtube]http://https://www.youtube.com/watch?v=nAEk3Ox_0SI[/video]