Slave Rule/Hidden Lurker

Slave can not take actions or block.

Could I use Hidden Lurker on a slave after a combat is over to make that slave enter combat with the blocking minion?

Yes you can.
Entering combat via Hidden Lurker is not an action.
In fact even a pentexed minion can play Hidden Lurker to pick a fight

Quick follow up, if a slave cannot take actions, what happens when they fall to 0 blood and would be forced to hunt?

Slaves can take actions and they can block. They cannot take undirected actions without their 'master' clan ready, though.

If you mean when a gargoyle is pentex'ed and has no blood; they simply stay untapped with no blood.

Slave: Some minions are identified as slaves to a specified clan. A slave cannot take a directed action if his controller doesn't control a ready member of the specified clan. Also, if a member of the specified clan controlled by the same Methuselah is blocked, the controller can tap the slave to cancel the combat and to untap the acting vampire and have the slave enter combat with the blocking minion instead.

Xaddam wrote:

Slaves can take actions and they can block. They cannot take undirected actions without their 'master' clan ready, though.

Xaddam, I think this is a typo. Slaves can take undirected actions, they can't take directed actions without their master clan out.

Almightyray wrote:

Quick follow up, if a slave cannot take actions, what happens when they fall to 0 blood and would be forced to hunt?

the slave would have to hunt since it is an undirested action.