That is all you can do, but why? There shouldn't be anything in there, if it is fogged over with a tint, then that is on the outside, either wetsand it, or buy new housings.
There was condensation and shit on the outside AND inside of my light... I used Crystal View on the outside and it turned out great, but there is still a bunch of gook on the inside... Need to flush it out and spread some silicon around the edges
I would let it air dry, then repeat a few times just to make sure it is all out and dried out, if you try to dry it with a cloth you could easily rub the "chrome" off the inside that is needed to reflect the light.