dark frames not working on DSS

[speckofdust]

Hello all, on the recent processing I did for veil nebula, I could not see any effect from using the dark frames on Deep Sky Stacker. Not sure why. I have tried all the various options such as remove hot pixels, dark optimisation, kappa sigma, median kappa sigma etc, but to no avail.

I have attached a selection of the image from a processed light frame and master dark frame ( generated by DSS). which show the same hot pixels. any help would be appreciated.