It's perfectly ok IMO. There was no detectable trace of acetone left, to my sense of smell and as we know, acetone is detectable by human noses in very small ppms.
It was relatively fast. I left it outside in a light breeze and within a few hours it had reduced to a small pool of what smelt like 90% water, 10% acetone. This IMO is the only weakness, that acetone dissolves the moisture content of the sample. It took another 24 hours to get rid of the remaining water and acetone. So if I use acetone again, I would make sure to dry - even dessicate - the sample prior to extraction.
It did produce a 'thin' hash. Pretty good method.