This is my method for sealing spoke type tires to make them tubeless. I have done this to 3 bikes, two Triumph Tigers '99 and '02, and one '07 KTM990S. I have put over 90,000 tubeless miles between the two Tigers and 20,000 miles so far on the KTM tubeless as of Sept 2009 with no problems. My "tubeless rides" included trips all the way to Prudhoe Bay, Alaska and full throttle top-speed speed runs at Bonneville Salt Flats and brutal Nevada desert. Thousands of miles of rocky, bumpy dirt and gravel roads, and temperatures from below freezing to scorching desert pavement temperatures, most often carrying a full set of luggage and often with a passenger. So far I have only used true tubeless tires in my tubeless conversions, such as Metzeler Tourances, Avon Distanzias, Continental TKC-80's (for Tiger), Pirelli Scorpions and Metzeler Karoo T (for 990S). The benefits of running tubeless are cooler running tires that last longer, less unsprung weight for more nimble handling, and super easy to quickly patch typical holes with a plug gun or "gummy worm" type patch kit from the outside, no need to remove tires.
** This information is offered as-is, as a DO AT YOUR OWN RISK project. I do not recommend any of the products or methods used here. This is just what I have done, nothing more.