Well, I've only detected creeks a couple of times, here is what I have learned:
Mud bottom creeks are easier to detect... I can't find any mud bottom creeks where I live though
Rocky bottom creeks move constantly, the "bottom" from last year is 3 feet deeper than it is this year, as in, rocks are pushed and cover the bottom so deeply, that finding anything more than a fresh pop tab has proven impossible for me in the few places that I have tried...
Using a hand scoop does not work on a creek like you would think it would. The target has to be shallow enough that you can see the bottom and be able to reach the bottom to actually scoop the target
Rock bottom creeks do not "shake out" of your scoop, you have to literally dump the rocks out somewhere or in your hand
Regular sand scoops, regardless of hand help or on a handle, do not work in rocky bottom creeks, as they are not built to withstand the constant grinding and weight of the rocky bottoms... get a scoop designed for rocks, or oyu will constantly be replacing your scoop.
I have personally had MUCH better luck on trails leading TO the creeks, and up on creek banks.
NONE of that is to say your area will be the same, just sharing my personal exeriences and what I have learned, in MY area.
My favorite creek side hunt story, the condensed version:
I was detecting a local creek, and a girl was sitting there drying on a towel, she had a smoke and asked me "Do people really lose alot of stuff for oyu to find at creeks?"
I said "You'd be surprised how easy it is to lose stuff...lol" She just shook her head in disbelief. A short time later she says "Well, good luck!" as she started for her car.
A few minutes later I worked my way over to see if SHE had lost anything.... I looked down on the ground where her towel had been, and she had forgotten both of her lighters! I put them in my pouch and used them for lighting the grill for over a year! THANKS for saving me a few dollars!