Need help with best practices for visualizing continuous data.

Hi,
I am new to cesium, so might have missed some obvious things.. Any pointers etc. will be helpful as well.

A simplified version of what we want to do is:

1. We have a stream of continuous data containing attributes like lat/lon (among others)
2. Whenever a new data item is received, we want to show something like a glowing bubble at the given lat/lon for few milliseconds and then make it disappear.

So far what we have done is:

For each entity received:

1. We create a "sampled property" that updates the radii of an ellipse from x to y over a period of 0.5 seconds.

2. We create a new entity with the ellipsoid property, with radii set to the above sampled property. We also set the "availability" of the entity using a TimeIntervalCollection with "start" = current time and "stop" = current + 0.5 sec.

This visually gives us what we want. A sample is up at http://mahi.usc.edu

but my question is if this is the right way to achieve this? One problem I see is that we are just adding entities, but never removing them. This might have perf. issues? How do i keep track of entities that are no longer "available" and remove them from the collection?

Please also let me know if i am on completely wrong track and this can be achieved using other cesium features (data sources?).