Overview
If you are interested in how the slaver’s enslaving mechanism works in this game then this guide is for you. Hope you could have a little fun with the information here.
Choose the right method for the right kind of target
Before you even go into sneaking mode, you should open the Slave Traders page on kenshi wiki. The info on wiki might not be up to date(for example on the Tech Hunters page it says tech hunter has 100 to both Machinists (100) and Mongrel (100) , and zero to other factions, but on the Anti-Slavers page you will find out that Tech Hunters actually has 15 toward anti-slavers) so your best bet is to save your game before doing anything and see what happens after things are done. Reload and change tactic if the result is not good.
Anyone will have the [Escaped Slave] tag added to them as soon as you manage to put shackles on them, and you can, for the majority of cases, carry them and walk around freely in a town afterwards. This tag will not work on everyone(like if you put shackles on Lord Phoenix and expect walking out the room with him like nothing happened it will not work, the Holy Nation guards will disregard the shackles and attack you). If you see the city guards aggroing on you that means you are doing this the wrong way.
Do not put shackles on Slave Traders. It does not work and will aggro all slave traders.
For the following factions, if you are carrying them(with shackles) while stepping inside a slave shop and being seen, the whole shop would attack:
Manhunters, Trader’s Guild, Slave Hunters, UC, etc.
Do not just walk in there with their friend on your back. The reason I asked you to read the wiki is to make sure you are not trying to enslave their friends just like that. If you want to make slaver enslave them, you would have to sneak them in and drop them on the shop floor without being seen. If the slaver boss or the slaver guards see them without you carrying them, they would enslave them no problem.
Some targets have unforeseen consequences if enslaved. Most targets, while having the [Escaped Slave] tag and being dropped on the police floor, will make the police aggro on them and attack them and then lock them up for trying to escape. If you do this to let say Empire Peasant, the Nomads will fight with the town guards because the Nomads is a friend of Empire Peasant. Just make sure not to involve unwanted factions before doing anything like this.
To get a pair of shackles, buy a slave and try to pick him/her up, the shackles might still be on her.
The best place to get big amount of free shackles, is somewhere near The Outlands, where you can find a lot of reaver slaves easily. Knock the slaves down and get their shackles.
How to quickly ally to Tech Hunters the vanilla way:
The squad member you dismissed will automatically join the Tech Hunter faction. You could do the following to quickly raise your relation with the Tech Hunter:
1. Acquire a pair of shackles.
2. Choose one of your guys to do this. Choose someone with 10 to 20 toughness so that he won’t die in a few hits.
3. Order that guy to attack something dangerous such as beak thing to injure him into state of unconscious.
4. Grab him onto your shoulder, put a pair of shackles on him, run into the slave shop nearby.
5. Dismiss him and drop him to the floor. The slave master will enslave him and you can buy his freedom repeatedly while he is unconscious.
What to do with Slaves and Captives who are trying to join you while you don’t want them?
Sometimes people would like to join your faction but you don’t accept new members anymore. Instead of dismissing them right away after they joined, you could do this:
The slave who just joined after following you for a mile or two out of the slaver camp, is eager to be of use to you but your faction is full now. First, you pick him up, then you talk to a slaver boss, choose the first option to sell him. After the slaver boss took him away from you, and put him in a cage with a pair of shackles, then and only then you dismiss him to turn him into a member of Tech Hunter. Then, talk to the slaver boss again, and buy the freedom of that Tech Hunter you just sold for the win.