The best way to get rid of the hot pixels is to shoot some darks with the lens cap on and to then process the lights and the darks in DSS.

As an FYI, I am attaching one dark file taken with the Olympus EM5ii for 60sec at ISO 1600. You will have to really blow it up to see the stuck pixels. I see red and blue and white. I am guessing that the white is really from green pixels of which there are as many greens as blue and red combined. There are also fainter pixels that probably are on their way to being hot pixels if I were to expose for more than 60 sec.

Now this camera has a way to learn stuck pixels, but it only does that for short shutter times and I have done the pixel calibration, and with shorter shutter times, you see zero stuck pixels. But this is 60 sec and as time goes by and based on the ISO level, some pixels start to show their true colors. I also see as I step through many darks using Faststone Image Viewer, that I don't see pixels coming and going. The same hot pixels in the first seem to be there in the last.

The good news is that after running the lights and darks through DSS, that this hot pixel mess is GONE in the final image.

By the way, I need to have Long Exposure Noise Reduction turned OFF to get all these stuck pixels. And the shorter the exposure time, the fewer of them that I get and the longer the exposure, the more of them that I get.

If Long Exposure Noise Reduction is turned on, the camera takes two shots, figures out the stuck pixels and noise, and then produces a clean image. The experts always say to not use Long Exposure Noise Reduction and the results will be better.

This image was taken with the Olympus EM5ii and I used Silent Electronic Shutter. Olympus allows the Long Exposure Noise Reduction to be turned off in this mode. But my Sony A6300 does not allow Long Exposure Noise Reduction to be turned off in Silent Electronic Shutter Mode with the result that if you shoot darks, they look really, really clean! And are probably not of much use. But the lights are clean too. For Sony, the rules are different if you switch to mechanical shutter, and you can switch off Long Exposure Noise Reduction.

Another issue I looked at is whether of not silent shutter mode reduces dynamic range. Some cameras reduce from 12-bits to 10-bits when using silent mode. This site here did some testing and finds that the EM5ii does not seem to scale things back, while at the same time showing the Panasonic GH4 does scale back the dynamic range in silent shutter mode.

http://m43photo.blogspot.com/2015/04/e-m5-ii-shutters.html

Also was able to find that the Sony A6300 does have lower dynamic range in silent electronic shutter, thus so far it seems like the EM5ii is a better choice for Astro images.

I also tried to get a list of what cameras can capture in 14-bit RAW and from what I can find, it is only the end end cameras with the really large mega Pixel counts. I think this leaves out all APS-C and m43 type cameras.