moisten your vermiculite 50/50 by weight with clean cool boiled water,it should clump together when squeezed by hand but not drip water,damp but not wet,if that makes sense?sit them on top half buried and put a damp paper towel over the top,cover with the lid and just float them as you are.Check weekly.if the paper is dry moisten it again,if not leave it till next time,should not need alot if any more moisture in such a place.depending on temp have had them out in 65 days but there is no set time,if they stay nice and white like a mushroom should be good,if they dry up and wither after 2 weeks or so no good.