If you have space in a field, why not just put the plants in the ground? It seems that a big 55 gallon drum just sittin' there in the middle of a big ol' field would look suspicious!
Plus unless you bury the drum, you're going to get hot roots=not happy plants.
Save that drum as a rain barrel so you don't have to tote water all the time.

Germ your seeds in a damp paper towel. A facecloth might be tricky because the taproot might get stuck in the terry cloth and break when you try to plant the seed.

BTW it's a bit late to start outdoors from seed, but still good practice and you can still harvest a bit of bud.