I have used screwdrivers, shrimp deveiners, big landscape spikes, and lots of other things. Probably an ice pick would be too light. Most of the tent stakes I have been around might well be too bendy also. Doesn't mean you will not find the ultimate one.
A 10 inch land scape spike with the point hammered down does a great job. And you get to put some crown knots on it for a handle.
You are limited only by your imagination. Which is why I could only think of three things to list. But I bet if I dug in my knot box, there would be lots of other things.
Good luck with it,
terry