i heard play sand works just fine, as long as you rinse it thoroughly. by that i mean run water through it copiously, and stir it around until the water is no longer cloudy. if you do this with tap water, after rinsing, i would let it sit overnight to off gas the chlorine. then maybe as an added precaution when you add it to your tank stir it around a bit and do a few water changes until its not cloudy anymore.
and as far as marine sand and pool sand goes, i believe the caudata article is correct, there are probably chemicals added to the sand. all marine sand is is crushed up pieces of coral, (technically passed through the gut of parrotfish) which is made of calcium carbonate (i think) so it would make your water too acidic.
a trick for cleaning the sand, aside from stirring up the whole substrate, a trick you could try is moving the vacuum in a small circular motion over the sand. this creates a small current and gently lifts the waste without removing too much sand.
hope that helps!