The money you lose doing alchemy to level it up is more than it cost to purify them with the NPC....
And therefore I go slowly.
I have node for purified water (one of the worst nodes to connect).
Also "grind" gathering with river water from alts (not best grind but afk).
In addition, this water gives me processing exp and gold.
I have mushrooms for free from node.
So I only buy wild grass which is / was cheap (but also I can get it for free when pick herbs for fruits).
And as I wrote earlier I am producing Elixir of Concentration and packed in artisan boxes.
Thus the gain from the imperial box is 99% of its value.
Not bad in my opinion.
Let's also count the cost of cleaning:
Black Gem Fragment x10 - 4m
Black Stone (Weapon) or 1,2m
Black Stone (Armor) x10 - 1,1m
Powder of Flame x50 - 100k (most time free)
Clear Liquid Reagent x50 - 230k (most time free)
So we have 5,5m vs 20m.
you have to look at what it really is.
Another gold sink gambling addiction.
it is supposd to be huge silver sink for guys that want bis stones "now"