I have two kuhlis that have been sort of shifted around, i guess u they are last the remnants of my pre cichlid community tank. Initially I gave them to a buddy because I didnt think they would do well with my mixed african juvies (nevere actually tried it). He put them in a 55g with 2 fronts, a 6" dom male, and a 4" sub dom male, and the kuhlis apparently did fine for several months until he moved and combined tanks and returned them to me for fear or their safety (however when we moved the tank we didnt even know if they were still there because we hadnt seen them in so long).
Their new house is my 10g fry tank that always has 30-50 babies, and they are doing great there, fantastic cleaners those guys. I would recommend them for that purpose, but when they were with the fronts they almost never came out. Now they come out all day long and eat, or just rest on the sand or fake plants, they are very happy. I think with dems tho, u might never see them, or even worse if u know what I mean. If u decide to do it tho please post and tell us how it works, they are really neat fish, just not very tough IMO.
I have/had a Tiger Loach in my Mbuna tank. I don't know if he is still alive. When I got him he was out all the time and there was never a bad interaction between him and my cichlids EVER! Then all of a sudden he started hiding a lot in my rockwork and would see him every few days as he would pop out on occasion. I haven't seen him in like 2 months at least. Probably dead. But I think they are a great loach with Mbuna and they are an AWESOME fish.
I would recommend going with the yoyos. I've had lots of Kuhlis in the past, and they very rarely come out and play. I now have four yoyos, and they're the most playful, active loaches I've ever owned. They're also really good scavengers, and I've seen them buried up past their gills in the rocks digging for food quite often.
Also, they're the hardiest fish I've ever owned. I had a tank spring a leak when I was on vacation, and my uncle took the tank outside (because he didn't know what else to do with it). Temps ranging between 35 and 70, and only 6in of water in the tank for three days. My yoyo was the only fish that survived.