Is it good or bad?
The good part
is that mill due etc and other things or critters won't be around your pool to enjoy a swim. It even , when done solid , might outlast you and your family.
The bad part is that it is toxic. How toxic is it?
It is so toxic that it shall never get in the ground (water).
If you'd work with the preservativ substance it is so toxic that you
-always have to wear special protectiv clothing
-never get in contact with it, especially if you have a cut or scratch
-have to change your work cloth at least twice a week ( not that you wouldn't)
-you can't spray it in the open on wood
-when you get out of your protectiv cloth for lunch you have to wash off (and you do this anyway)
and of course you can't smoke which might or might not improve your health - I guess that doen't matter anymore when you work with this stuff.
Why would it be so bad to have it at your swimming pool? That stuff bleeds out.
But your neighbor has a deck out of PT material and he lives with it?!
To me it is more a question of how much toxic material I would like around me -
as much as necessary but as least as possible.
Would you be able to get a lasting structure without the chemical component?
Sure, wood is hydroscopic, it can absorbe and release moisture without taking damage.The moisture diffusion needs to be thought through and the material you use where I would refer you to your friendly craftsman around the corner.
