New Pressure Treated Fence

I am getting ready to quote staining a 260 ft long 6 foot high privacy fence. It was installed in November 2016 so it's right at about 5 months old. The installer told the customer it could be stained in the spring so she is looking to get it stained this month. A website called Texas Wood Products had this to say about staining fairly new pressure treated wood. I wanted to get other opinions. I don't want to advise this customer that it is OK to stain now if it would be better to wait. Here is what Texas Wood Products says, 

Pressure Treated New Wood: New pressure treated wood should always be allowed to weather for at least one year after construction. This is very important because the pores of the wood are clogged with chemicals that will not allow the stain to properly penetrate and bond. After one year, clean the wood thoroughly with a sodium hydroxide or percarbonate wood cleaner. Never use pressure higher than 1500 psi when cleaning wood! After cleaning, neutralize and restore pH with an acidic brightener, rinse thoroughly and allow to dry completely before application of Baker's Gray Away.

I noticed these yellowish-green powdery spots that smear when you rub your finger on the fence. I am posting picture here to view. I think it is the chemicals from treating the fence that are moving to the surface.