did they manage to make bath salts?

Yes, in fact they were so successful that they got into conflict with the city's criminal underworld. An underworld that they promptly decapitated. This left a power vacuum that would cause the city government to collapse as they tried to fight the surge of violence with institutions weakened by the corruption caused by the drug trade. Eventually the violence was stopped when the queen sent in troops to assist the guards, but they also ended up taking a good chunk of the surviving population who were freed slaves or the decedents of freed slaves to return them to their "rightful masters" (The slaves were able to hide before as the city was an unimportant mining settlement far from the capital and the coastal plains where slavery was culturally accepted. Also to be clear the army was sent in as the players did not try to quell the violence themselves).

But on the plus side the chaos made it pretty easy to sell their drugs, with the guards focusing on quelling the violence it was pretty easy to slip a few drug trades under the radar.