How can I increase corrosion protection using Toyota pink coolant?

Hi Guys,

My problem is this I want to use Toyota Pink coolant because it's formulated for our rads/engines and red isn't stocked anywhere near where i live. But because it's only a 55/45 pre-mix and with the water that is still in the engine block (after a flush and i can't find that drain valve on the engine block to save my life). My coolant mixture is probably below 50 coolant. I'd like to have it around 60/40 for some increased corrosion protection. I would like extra corrosion protection because when i flushed the coolant it looked like chocolate milk.

I figure people that use the toyota pink should have similar problems. I was looking at redline water wetter as an additive to increase my corrosion protection will this work? How have other people increased there corrosion protection using toyota pink?

Thanks,