Raytracing Denoiser?

Im using 4.25 and still cant get a clean reflection with raytrace.
As said here, the reflection denoise works when using 1 reflection sample.

Is there anyone from epic that can point us to the right direction?
All raytrace video demos from epic have clean reflections.

I found this talk showing the raytrace + denoise inside unreal, and in my tests the result is not as good as showed in the video.