Prismaco,
Several ways to do it. The PVC tube works pretty well...you are still going to have some clowd though.
I have heard of people leaving it in a baggy dropping it all the way to the sand bed. then slowly "easing" the baggy out from under the sand...this method doesn't really allow the sand to "drop" thus you don't get a gravity related sand storm...either way you are going to get SOME cloudiness....the amount of cloudiness is directly related to how slow, and careful you do it.....and of course just how bad Mr Murphy hates you.
Dave