You know, from months of experience since I started this hobby of ours, I realized that no coaxing will induce the plant to send out roots if it is not in the mood.
I do use Superthrive and KLN and they do help but if the plant doesn't want to send out roots, it doesn't. It has an effect on some orchids right away but on others, it's like waiting for the end of the world.
I wasn't paying attention to other orchids and then suddenly I realize that they grew a lot of roots (renanthera), so just wait and do your normal thing and use Superthrive or KLN. Sphag and bag never worked for me.
Oh, by the way, do not cut off dead roots or roots that look like they are dead! I have had many instances where the roots looked and felt dead but then after a while a root formed on it! I do keep my orchid roots exposed though with little or no medium so the dead roots don't rot, they just sit there.
Diane