If you have access to a couple of 2 oz containers, by all means make use of them. 2 oz is enough sample for analysis anyway.

If you do discover sediments or other foreign matter after thaw-out, they can be filtered out. An old section of pantyhose works wonders for the job. :thumbsup:
And for a peace of mind, test the sample with a validity strip to make sure the pH, SG, and creatinine check out okay.