I picked up the mini trampoline as planned yesterday after work and I love it. I jumped around for about 40 minutes last night and had a good old time.
I did a strand test on a sample of my hair yesterday to see if it is hena-able, and to my chagrin, it is not. The hairs that were not yet grey got darker, but the white hairs remained white. I think I'm just going to leave my hair grey and see how it goes. I've endured enough hair processing to last a lifetime already and it's time to put my money to better use. For now at least.