I use a very large (1000L+) tumbler made from an old oil tank. I don't have trash pandas, but I definitely have bears.
I find it works best as a two step process: I fill the tumbler full of materials (scraps, leaves, clippings) over the
course of a month or two and let it do it's thing, giving it a tumble weekly. After the contents are no longer recognizable as 'food' I transfer to an open pile, and start filling the tumbler with fresh compostables.
I'd say it takes a bit longer, but eventually gives the same product.
I very much second Kc's suggestion of inoculating with native soil. I also reserve the larger incompletely composted chunks left over after sifting, and cycle them through again.