I just started using the Viber 125Hz from www.axeldental.net/www.ecwid.net which is a dupe of the Vpro+, which is more effective than the Acceledent (shorter usage time). I had it for almost a year, but didn't use it, because I thought it didn't work, but it does.
Read more about this misunderstanding here:
I also have one for sale if anyone wants it.
Wish me luck. I can feel the vibrations all the way to my jaw and cheekbones, so I hope it will make my whole face a bit more malleable for Mewing :).