Need some Advice - Have sanded, Need to strip??

We have a pressure treated deck and nothing has been applied to the deck over the past 7 years. The grey has been pressure washed off several times and that is it.

So far, we have:

1. Cleaned with TSP/Oxi-Clean.

2. Pressure Washed

3. Sanded. (Wow, never want to do that again. Holy smokes)

4. Brightener Applied.

The previous owner had applied some type of Sealant (or possibly a toner, 7 years ago.) There are a few areas that still bead water to this day. (Small sections right against the pool and some areas of horizontal boards.)

95% of the deck soaks up water like a sponge.

It was when applying the brightener that I started to get concerned and wonder if I should have stripped the wood to begin with. It was the first time the wood had been wet since sanding, and the inconsistencies in the appearance started to show. Maybe I am over analyzing this.

With everything we have done, would there be a need to chemically strip the deck?

Any advice would be appreciated.

Thanks,
Pat