Yep, That's the method I'm going with this first year around. I've planted long rows of asparagus in the past, and had a time with voles rooting down to them, and eating the rizomes. I'm concerned about this happening with the hops, so It's cut out buckets/pots at least this year.
Use at least a 3 gallon...some say one gal
And be sure the lip of the bucket is lower than the soil surface by a few inches...this will allow rain water to enter into the top portion of the bucket.