Bern,
The mossie guys are using a swimming pool filter materials.
It is super slippery and is full of holes so it drains.
I'm told it is imported from NZ.
I think it is the best material I've seen so far.
I think Erwin Sails imports it just or this purpose.

Regards,
Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!