Don’t be hoodwinked by looking at trichs before the plant is finished. I’m not saying that every single white pistil has to turn brown and recede, but it looks like your buds have some significant swelling left.
If the plant is healthy and has plenty of green leaves remaining, I would give it more time. Just because you have a fair number of cloudy & amber trichs now doesn’t mean they will all degrade if U let it grow another 2 weeks. I’ve had plants with mostly cloudy trichs and let them go 2-3 weeks, hoping for some ambers. They never came.
As for the flushing, do whatever you prefer….its your grow. I grow organically and don’t flush anything but my toilet.
I would give just water, let her fade a bit and harvest in a couple weeks. Nice looking grow for sure. Good job.