I recently spent sometime looking for a rocket in a species of tall grass known locally as "corn". This particular field of corn was on the order of 2 feet taller than me (I'm not tall). It didn't help that my rocket was olive drab, though had a 36" bright orange chute attached.
I know my experience is far from unique, but its the first time I've had to do it. I had a Pratt Hobbies screamer attached, but I've found that it seems to vary considerably in effectiveness. My theory was that if I walked in the right direction, I'd get close enough to be able to hear it. I spent 45 minutes out there, only to find that one's sense of direction is wonky when you have to sort of move in X-Y directions that run counter to your bearing, and you can't see any landmarks particularly well (or at all). I eventually came in, realized I'd gone off about 15 degrees to far to one side, and tried again on an adjusted bearing (relying only on internal guidance for direction). That time, I got within a few rows of the rocket, or at least the nose cone where the screamer was, close enough to hear it. I popped over through the rows and found the cone, chute, screamer (and my JLCR) all hanging about head height in the corn in front of me. The body was about 15', with the shock cord all stretched out.
Anyway, the lesson learned here was that screamers have limitations, or at least the one I have does. One has to be a lot closer than I'd imagined in order to hear it. In a corn field, its possible to walk past fairly close without hearing it, though I wonder if the corn itself dampened the sound transmission. Time to try a different device, I think. The Pratt Hobbies screamer was inexpensive, but not that loud. I think the results wound be better in grass, for corn, I think I need one that is considerably louder.