If a PC obtains the Corrupted Flesh feat http://www.d20pfsrd.com/feats/general-feats/corrupted-flesh/ how long is the enemy sickened? And is there anyway (a suit or some sort of breathing apparatus) the PC's allies could be protected and not be affected by this?
Giving the limited information I have, I would make it persistent while within range or until you save.
Ahh, ya very limited indeed. Any ways for allies to defend vs it while in range? Toxin sponge may work. This feat may be suitable on a wild barbarian
I guess that would work. The main problem I see with this it's that it is a persistent stench. It's not some ability you can turn off. Think of some way that all your party members can get toxic immunity or when you sleep and travel (and hopefully never into cities) that you can arrange to be at least 30 feet away from each other and for battle just chug a couple of poison resistance potions.
Overall I'm pretty sure that it's not really worth it considering all the external costs.
Trish makes a good point though, walking around town with that Stench could be an issue unless one could mask it with a powerful perfume or something