Kind of a Farm thing....maybe?
I have two extra gallons of Perma-chink Log Wash.
It is for washing wood before you stain it.
Used it on a log cabin and ordered too much, to costly to
ship it back to TN.
The cost is $34 a gallon, I did my fence with one,
and still have two more I'll sell for $22 each.
But, you'll have to come pick them up, they are too heavy
to ship cheaply!!
Won't bleach grey wood, it is phosphoric acid based.