I have 3 dalek compost bins full of pony poo which had been there for a couple of months. Can I put some earth on top and grow courgettes/squash in them?
Definitely, they'll love that.
Only thing is, if the top is quite narrow you need a way of watering them without splashing the leaves. I cut the bottom off a milk carton & sink it into the edge at an angle, like a big funnel. Or you could use an actual funnel or a length if pipe.