Ha! I've been refilling a Wilkinson dispenser for the wife by sliding fresh blades back in while holding the plastic stop down. She uses the bottom for her blade bank, so I've been hooking the used blades out with a machinist scribe and throwing her dead soldiers in my tin can with a slot. In fact, I just did this before reading this post!
I also have many of the modern ASR dispensers that are two sided. After reading this and the Wiki article I took the top off an empty (It's just a flat piece that is held in place by recesses in the plastic body) by gently prying with a small flat bladed screwdriver, filled 'er up with Sharks and popped the top back on with simple finger pressure. This turned a half hour endeavor into a five minute snap.
The only downside I can see is the potential to gouge up the dispenser body with repeated prying, but if you're careful that shouldn't be an issue.
"He must be a king. He hasn't got Williams all over 'im!" - cb91710
I spend my knights at the Veg Table.