Do you have any de-noise tools? If you'd like, link me one of those totality raw's and I can try running it through the one I use.
I don't use anything, generally. There's a BlurXterminator plug-in in PixInsight I use for deep-space astro shots, but in general I try keeping the ISO setting low to prevent noise from being generated in the first place - it's a relic from my film days, I guess.
Dunno if this will work, but there's an RW2 file here:
I'm sure the high ISO number contributed, given how clear the pre-totality ISO 100 shots look, but on the other hand the Read Noise in the S5's sensor is pretty low at anything above ISO 600 or so, ...I think the ISO 6400 may have been part of it; I got the best results with shutter speed settings that kept the ISO between 800 and 1600.