I've added a point_push entity to my map. This entity is enabled only for a short period of time. Yet after disabling the point_push the dust cloud whirling towards the entity doesn't disappear. Even when I kill the point_push the dust cloud remains. Does anyone understand/know this phenomena. I would really like to get rid of that dust ... maybe there is a way to stop it from appearing altogether?

I've just found another important detail to the effect that I described: the 'perpetual' dust cloud is due to both Portals being close to the point_push entity. If at least one portal is a bit farther away the dust cloud doesn't even appear (or at least I think so after a bit of testing). Does that make sense? If so how and why? And how can I prevent that from happening?

point_pushes in Portal 2 are used for the scrapped Diversity Vents. Valve enhanced the code so the push-effect can work through portals. I thought that the particle effect would only appear as long as there is a info_particle_system entity in the near of the point_push, but it seems like it works without.

I use point_push-entites too but their magnitude isn't very strong which means that I don't get a visible effect. Maybe you can do that too and see if it helps. Try using trigger_pushes to attract / push entities if you need a stronger push, or even try a trigger_catapult. Also maybe multiple point_push with the same, low magnitude can create a stronger push without the particles; I don't know. Play around with some workarounds .

OK,bumping this topic...

After some more tests it appears that this phenomenon is probably coded into the Portal 2 code. If a point_push is going through a portal it produces that dust cloud in some instances. The problem is that the dust cloud is not being disabled when the point_push is being disabled.

Therefore, I have a new set of questions:
1. Does anybody know how to get rid of the dust cloud with another entity?
2. Does anybody know how to tell hammer that the dust cloud shouldn't even appear in the first place?

Unfortunately, if it's hardcoded, both of those are impossible. It's like the new glitch with the point_spotlight, there's no way to get rid of it. You just need to avoid the entity in the first place.