I've been using rubbermaid tubs, but may switch to 5 gallon buckets.
Today I watched my faithful layer, my cuckoo Marans, go around a small coop, under a big growth of blackberries, past a couple rolls of chainlink fence and behind the hay barn to find an old 5 gallon bucket laying on it's side. Followed her back there, it took me 20 minutes to hack all the black berries away so I could get there. Sure enough, two pretty dark brown eggs! I'd wondered what happened to her egg yesterday.....if she likes them so much, I may start using them in the coop. Much easier for me to get to!
We put home depot buckets in the first coop we ever built with a nice perch on the fronts & filled with straw but none of our hens ever went near them. Each generation of chickens we've had has been different though so what some like others might not. We've had some that wont go near the Rubbermaid tubs because they're too light (even with a paver in the bottom) & others who liked them. My current flock is laying in wood boxes that we built & some of them will only lay in the raised nests & others will only lay in the ducks box that's on the ground. I haven't had any girls that hide their eggs ... yet.