Alternative to the V2 sponge.
 

Poundland are selling a sponge that is exactly the same as the V2 sponge from Visorvision.
It is called Clean Zone Sponge Eraser. The sponge size is 19 x12 cm and can be easily cut down. At the moment they are selling them 2 for a £1.
I've tried it on my helmet/visor as well as on the bike and it works perfectly well. Got rid of the bugs and marks with just a little bit of water.
If I can find somewhere else that is cheaper I will certainly stock up on this product.

Ste.