I just registered (love the game) to add some observations regarding how germs on newly dug slime behave in chlorine:
Mining a slime tile with 1,5 million germs so it falls into chlorine (2k pressure) cause the number of germs to rapidly decrease to just above 1 million and then stop there.
If the piece of slime is then moved by sweeping it to a container situated in chlorine the reduction in germs kicks off again, this time stopping at 99 germs.
Now moving the slime to another container passing 3 ore scrubbers will reduce the amount of germs further BUT still not completely cleaning the slime.
Sometimes sweeping the slime to a container does not restart the reduction in germs but dropping it out of the container will once again start the reduction.
This amount of micromanagement is a bit too much imho, coupled with the fact that 3 ore scrubbers is not reliably cleaning slime with just 99 germs makes mining slime biomes a hassle.