I know when we did putricide we had a handful of ppl stay on putri for that exact reason, they couldn't get their dmg up high enough on the oozes to make a huge difference so it was more economical for them to stay on the boss. Of course this depends on your class and rotation i have no idea what spec you are as a rogue, or even if you're a feral druid so i can't troubleshoot that.
Primarily make sure you're not getting hit in the face with malleables and you're not walking through the choking gas bombs, those WILL KILL YOUR DPS. If you're doing good with that, bring your problem to your RL or DPS officer and ask them for advice as well as asking if it might just be better for you to stay on putri constantly.
If you do end up focusing on putricide 100% of the time be sure to watch your DPS! you'll have a very angry raid if you stop paying attention and phase him too soon. Also, as a tank i drop the choking gas bombs between kiting movements so melee doesn't have to worry about them. But if you're on putri all the time you'll have to keep an eye on DBM and stand in front of putri for a few seconds until he drops choking gas bomb and tank pulls him clear of it.
Hope that helps! If you post an armory link and rotation myself or someone else may be able to troubleshoot it more for you