Container potatoes and veg

Watched a couple of Monty's videos re growing spuds and shallots in containers....he had a bin for the spuds but just a metal bucket for the shallots. 

Has anyone tried the shallots like this? Was thinking of trying it with shallots and red onions, and maybe even parsnips, if I can get big enough buckets...any thoughts??

I take it the type of container doesn't matter as long as there are drainage holes in the bottom?

Cheers