Around my area they use the Torco RFF 15wt fork oil just because it's readily available. It seemingly works as I have a couple of RV tech friends that haven't said any different. I imagine any of the recommendations work as long as you follow the instructions. There's more to it than just sucking out a quart and replacing it if you want quicker results.
http://www.lci1.com/images/support/lipsheet/0295.pdf