http://www.ehow.com/guide_14-http://www.ehow.com/guide_14-travel.html.htmlwww.ehow.comhttp://www.ehow.com/how_4513357_dump-tanks-rv.htmlIt used to be, back when campers camped in tents it was okay to dump gray water on the ground. But now that campers have toilets in their RVs it's not acceptable to dump your grey water (sink and bath water) just anywhere and your black tank (waste from toilet) should always be disposed of properly. ** Note...my video of my husband dumping out our tank is not exactly a step by step instructional video just an off the cuff moment recording-just for fun** RV holding tanks are used to hold, or store waste water until a sewer system is available to empty the tanks. Because little water is used, in comparison to a domestic waste water system, RV holding tank wastewater is far more concentrated. There are special chemicals you should use, especially in the black tank, to reduce odors and the buildup of solids in the tank, which could cause problems down the road. There are many brands and types on the market, from powder to liquid. Published on 9/15/2008http://www.ehow.com/tips_4513357.htmlGreat article! I wrote a very similar one last year. In your how-to, step 8 calls for using a wand down the toilet. This can be a bit of a chore and generally makes people impatient when waiting in the dump line. If you're by yourself, then go for it. Otherwise, a holding tank rinser would be advisable as they are very easy to connect up and only take a minute of extra time while dumping.