I have only WS'ed with open ended jugs.I sow annual poppies that way.Birds and heavy rains were taking my seeds out.
I use 2 plant stakes to anchor the jugs down.I use half gallon because thats all I have.
Poppies Sown November 4 note crossed plant stakes thru the top
Mixed poppies in a gallon,note the crossed plant stakes.If you only use one stake the jug will twirrlaround it in the wind and the seeds will end up scattered.