The One Power + The True Power

The TP is seductive to those who belong to the DO. I would think channeling the TP and being Lightside would be akin to the taint pre-cleansing and affected Rand aversely instead of making him hunger to use the TP more. That was my interpretation.

How does this theory conform to Rand's own experience with it?

I don't know, but I think I'll be a little disappointed if nothing else comes of Rand's TP use.

As QuiteAiel says, Brandon claimed that we haven't seen the last consequence if it.

He had not used the power for very long before it was cleansed

But he has been channeling quite a bit more than regular Asha'man. The use of Callandor and the Access Key alone should account for part of that, I think.