Well, it IS pretty insane, though let's take a closer look...
Taking my own character as an example. Dude has 60 blood charges max (10 HD times a score mod of +6). If he chose to up his charisma to 32, that would give him a new whooping maximum of 110 charges.
In order to fill back up to max, he would need to make a total of 60 successful drain attacks (30 in a Septette stance because of Light Eater). Even assuming he drains one Con at a time to savor the meal, that would mean he'd need 30 points worth of Constitution in snacks to top himself off, so... we're basically talking about a freakin' bloodbath here.
In theory though, he could just have what I'd like to call a "Blood Doll" handy. This is basically a character with Naberius bound and Con pumped through the roof. Let's say... 18 con. He drains up to 16 points of con and gains 64 blood charges, and 16 hours later, she's all set to be sucked dry again.
...You know, I could actually see a market for "foodstuffs" designed that way...
EDIT: And on that note, can I have a Blood Doll Einherjar?
EDIT2: What happens if one blood drains a creature summoned through Nocturne in the Moonlight?