Tubeless conversion on schrader valve rims Situtation
I have an old hardtail collecting dust. I occurred to me that a rigid fork, and some wide (i.e. &gt;50 mm), slick tires would make it a pretty ideal commuter for me.
Then I thought it'd be great the setup those wide, slick tires tubeless.
Unfortunately, I just recalled that the rims on that bike are drilled for schrader valves. I had forgotten because when I bought the bike I immediately purchased the grommets necessary to use presta valves on the rim.
I notice two things

The first is that it doesn't appear the tubeless schrader valves are readily available (http://www.universalcycles.com/search.php?q=tubeless+valve)
The Stans conversion kit comes with tape with a valve already attached (http://www.universalcycles.com/shopping/product_details.php?id=1208)

Question:
Will leaving those grommets in place allow me to set up the rims tubeless, or am I stuck running tubes since the are rims drilled for schrader valves?
I mean, put enough Stans in to the wheels, and you can run tubeless on just about any rim setup.  

If you have non-tubeless tires, you may run in to an issue with the tires themselves being too porous, and that is hard to get around.  But I imagine that the combination of rim-tape, grommet, and Stans will be fine.  The rubber wedge/plug thing on the base of the Stans valve stems is pretty wide, I bet it would work even without the grommet.