[MERGED PR] Purgatives and dialysis machine rebalance

[Lord_earthfire]

To be clear my big issue with pentetic acid isn't necessarily how fast it is, but the fact that it works on everything and has virtualy no downside. I don't think a numbers nerf would change anything to that. It will still be at the top of purgatives. It would still neuter any lasting consequences of poisoning on most RP shifts.

This PR is just about the big purgative chems in general. I agree that we should maybe do something about specifically pentetic acid at some point, but i think that would be a PR that solely reworks that specific chem instead of one that tries to do a more general balance shift like this one.