some clever bugger on a thread about bamboo farming suggested soaking in salt water..IMO brilliant ..never seen a softwood bit of driftwood attacked by land born rot or insects.
Building with wood? ..big bit of pipe or trough immerse beams etc in salt water..better than toxic expensive commercial products methinks ..antibiotic too?
Probably still take varnish or with a bit of sanding...works on boats...salt water exposed wood is never attacked by land born rot.?