I tried topaz>denoise>rawlight but I didn't like the result
What version of topaz are you using?
(Also Topaz is a photo editing software. All of the built in presets were meant for full color photographs, not black and white comics. You can use Topaz Denoise for scanlation, but you have to learn what the various settings do and how you should manipulate them depending on the raw, not click "raw light", "raw moderate", or "raw strong" and hope one of them works.)
Can you post the unedited raw that you used?
I'm using topaz denoise 5
Try using surface blur, then level it.
This will wash out most of the grays though.