I've found that most of it happens outside the vst. Be it, distortion, modulation, usually when I see guys talk about neurofunk bass and such they use NI Kontakt, which is really just a lot of effects you can apply to your reese you have made in Massive, for instance, and the sampled and put into kontakt (I don't have Kontakt, so I have limited experience with it, though). I still have a hard time making those moving synths, but it helps alot to sample it (Or just put some effects on the inserts of the vst), and then go wherever you like, no boundaries. Usually when I wanna make something gritty I just slam ohmicide on massive, and experiement till satisfied - sometimes loads of layered distortion.