[Splash & dash]

And can anyone clarify what effect SH has on wood ? Say.. after a good dual soaking?

It will kill any algy and bleach the surface of the wood a little depending on the type of timber strength of mix and dwell time : if the timber is given a good soaking with the garden hose first so that it is saturated the vast majority of the hypo and surficant will stay on the surface of the timber which is ware you want it it’s not going to do it’s job on the surface if the wood had absorbed it all , hypo is used quite extensively in the timber industry to alter the surface colour of wood to age it etc

[Don Kee]

Benz biocide is called Biocide. 

Biocides are mould/algae etc...removers/cleaners. ‘Benz’ are a brand, they haven’t  copywritten the term ‘biocide’.

[Slacky]

It was a joke.