Additive A certainly will make your clay rather skunky after a few months……

It doesn’t smell that good when it’s fresh…… but give it time……

That strange black mold…… I know exactly what you’re talking about…..

It’s rather harmless……. I’m pretty sure it’s derived from cornstarch, or something like that……

I’d reccomend liquefying it, if you choose to use it……. What you say about trimming….. 1-2% rock hard…. sounds about right……

Something like vee gum or bentonite of some sorts is probably a better bet, as far as a porcelain plasticizer……