Oh I've gotten candles to work for Kuppers! It's very tricky though, this is what I do: First try to figure out exactly where she's going to spawn by either fucking Tess or just waiting till she spawns (I think the spawn point doesn't move, might be wrong). Now, get her to spawn again, but before she appears, make sure you leave a lit candle on the floor next to the spawn point (left or right), and finally, when she spawns, light the second candle on the opposite side (so she's between both candles). The problem is that kuppers usually extinguish candles, so it's kinda hard to keep the first candle lit before they spawn. The other issue is that the candles have a short "range", they both have to be kinda close to the spawn point. I think you're supposed to do this when she has just spawned and still isn't moving. It's hard but it works. Don't know if my weird explanation works for you lol. I think there's a little video somewhere in the 'how to play' or 'tools' section of the menu showing how to do it.