Your question is really a matter of opinion.. Yes its fine enough to make some knock you on your ass moroccan hash, but not fine enough to make the purest product..
On Roseman's point, trichromes have a property called 'glass transition', and that occurs at ~9°C.. Warmer than that and things get sticky, cooler than that and things keep like glass beads, they may crack/shatter, but they won't gum up your screen forcing you to scrap and damage it as suggested above.. Those screens ain't cheap!
I grew up using those hippy hankerchiefs for the job.. Actually got a halfass decent purity if you were really gentle, and only rubbed the batch slightly first run, then saved the leftovers for lesser quality runs..