OK, rinsing isn't bad, it just isn't necessary. If you can do it without any direct agitation you will not get a dust storm with Flourite of Onyx Sand or the like. Sorry if this is late, but maybe you can try this next time.
This works best if you have a hose that has variable pressure (I use Python water changer), or you can do things more slowly by using a standard siphon, but you need a height difference with the siphon.
I layered a mosquito screen (purchased at Walmart in a roll) on top of the flourite to minimize any agitation and allow soaking as well. It was cut to size and folded into three layers. I lay my Python tube flat on top of the screen and turn the water on the lowest pressure possible, so the water just trickles out. As the water soaks into the Flourite and covers it, the screeen, and the tube, you can adjust the pressure up gradually without any dust kicking up. The screen provides a barrier and helps keep floaters down as well.
The worst that happens is you get some of the original dust on the water surface and some bubbling on the sides of the tank, but this was a non-issue and didn't affect the water clarity. I do get little poofs of dust and air when I poking roots in the substrate for a few weeks, but it never amounts to anything much.
I took photos the last time I did this, though it was with Onyx Sand not Flourite. Same result with both.
No water
Layers of screen
Here we go...
I can still see the gravel
Out of focus, but you can see the film of dust I mentioned on the surface
Looking front to back, still see the screen and texture of the wall clearly
Full. Where's the dusty soup everyone talks about? You can kinda see the bubbles on the glass, I just scraped them off at some point
Here's that surface film again, not so bad, eh?
End result, again out of focus, but decent water clarity, don'tcha think?
