Wow!!
Looks trick, Ralph!!
Yes, I have used the salt-in-tubing trick and it works very well... When soldering tubing I use a small propane torch, pure silver solder, and acid flux. I first make sure the joint is making perfect contact, surround the joint to be soldered with insulating clay, flux the joint area, slice a small (very small) piece of solder off the roll and lay it on the joint, then hit it with the torch. In about 3-5 seconds it melts and instantly joins the parts with very little excess left to remove.
I learned this technique from Augie Hiscano, the metal master!!!