I checked the last 2 Wednesdays (June 2nd and 9th) and tried adding one to my cart every 20 minutes from 12pm to 4pm est, and couldn't get one.
The product page is kind of ambiguous... it seems like they're stocked every Wednesday afternoon, but it doesn't say for certain. Is this just a "try every Wednesday for the next couple months" sort of thing? ('Cause I'll do it!! - but... I'd like to be a bit more strategic about this if possible).