Sacrificial Undead?

[Kamikun]

I certainly don't claim to be any sort of expert in anything on the matter, but I was curious:
Say the BBEG happens to have a whole ton of low-level undead that he really can't do much with. Is there any way to get rid of them that would grant the BBEG some sort of bonus or power? Such as sacrificing them to gain some ability, etc, etc? Is there a feat, or a spell, or some obscure niche act that is capable of doing this, or is the BBEG pretty much limited to "terrorize the populace" with his army of ridiculously low-leveled minions?
Thanks all for your help, and sorry if it's been covered before!

[Doxkid]

*Aid another abuse
*Construction work
*Destructive retribution Healing
*Food for a Barghest (I think...It only specifies Humanoid, which a human zombie still is)
*'living' machinery
*Book of Vile Darkness sacrifice (Cant qualify for many bonuses, but you can still rack up a decent score. enough to get crafting points or a 24 hour buff)
*Target of spell (Door of decay, for example)
*Magic Jar'd body (worth noting because you might be able to find a real gem of a corpse and walk around as it

[TuggyNE]

*Food for a Barghest (I think...It only specifies Humanoid, which a human zombie still is)

Sadly, no. All zombies are now Undead:
The creature’s type changes to undead. It retains any subtypes except alignment subtypes and subtypes that indicate kind. So a human zombie has type Undead, no subtype.

Other than that your list looks pretty good.

[Jeff the Green]

Destroy them, then fabricate into more useful skeletons?

[Silva Stormrage]

Can you sacrifice them using BOVD's sacrificing rules? Or does that only work for living creatures. If you can sacrifice them you can get one wish and a bunch of free crafting XP.

[Starshade]

Make them carry an fortress around, row galleys, etc.