Indeed, this is the only way I know of to achieve this. You have to use the "Skyrim NPC Editor" to either modify the voice files of an existing NPC, or to else to create a brand new Khajiit NPC of your own design and give them one of the voice files which contains marriage dialogue. Make sure to add your new NPC to the marriage faction (follower faction too if you want), which can be done in the editor or in game using the console. You can even make an NPC that looks identical to your favourite one by copying their skin from the files provided in the editor. The voice file is really the only determining factor in whether they are marriable or not. I do not know the technical reasons for this. Perhaps someone with more insight into the way the files are put together can answer this. That said, there are some nice sounding non-khajiiti/standard voice files that suit a khajiit (well, a khajiiti female at the very least). For those wanting their own "harem" in their home with the original khajiit voice file, the easiest thing to do is to do the following: create a few basic khajiit NPCs in the Editor (optionally, you can choose an alternate voice file for them, which will usually open up the marriage dialogue options for both genders, and the follower dialogue for females). At the very least, give them the AI pack "DefaultStayAtCurrentLocation". This should make them move around and interact with the environment they are placed in, including performing ambient poses such as drinking and eating. You may want to experiment with the other AI packs to make them do other things, such as sleep. (My experimentation with the ai packs is limited so I cannot currently recommend any others). Give each npc a unique name, then in game open the console and type "help <npc name>" to get their unique ids. While in your house, type "player.placeatme <id> 1" to place a single copy of that npc in your home. Make sure you do this in your house as, unless you add more AI packs to the npc, they will stay where you place them. Do this for each unique khajiit npc you created in the editor and voila, you have yourself your own little harem of khajiit in your home! Unfortunately you won't be able to order them about with follower commands, as khajiit females (at least ones with the khajiit female voice files) cannot be made into followers either. You can at least do this with the males, and you can do this with a khajiiti female with a different voice file. Optional: If you gave them an alternative voice file to make them marriable or recruitable as a follower, you will need to do the following in game. Note that "Actor id" is different from the base id shown by "help <npc name>" which you used to spawn them. Actor id can be obtained by clicking on the spawned npc with the console open and will show up in the middle of the screen: "player.setrelationshiprank <actor id> 4" and "setrelationshiprank <actor id> 4" to set their relationship status with you to the highest rank. If you didn't add them to the marriage and follower factions in the editor, or if they somehow forgot which factions you put them in, you will also need select them in the console then do "addfac 5C84D 1" to add them to the potentialfollowers faction, and "addfac 19809 1" to add them to the marriage faction. This should open up the dialogue both for followers and for potential marriage, assuming you gave them a valid voice file. Hope this helps!
