The purported benefits include...
1) smoother cutting. I can confirm this. I can't quantify this so it's just a personal "feel"
2) less dust. I can confirm this I can't quantify this so it's just a personal "feel"
3) easier sanding. I can confirm this with a caveat: You must get most of the solution off and even let it dry a few days or else your sandpaper will just glide over the wood fibers and you'll end up sanding far longer than otherwise. It's just the same idea as wet-sanding. I can't quantify this so it's just a personal "feel"
4) fewer checking
*while letting roughouts sit before and during final turning*. I don't have comparative numbers ready for this at this time. So, it's just anecdotal and should be taken as such.
5) less warping
*while letting roughouts sit before and during final turning*. I don't have comparative numbers ready for this at this time. So, it's just anecdotal and should be taken as such.
6) more translucence in the final turning when using other techniques after final turning. I can not confirm this.
The use of a Liquid Dishwashing Detergent / Water solution is used before and during the turning process for the above purported benefits.
There's nothing magical, mysterious or secret about the use of the LDD/Water solution. I'm not completely sure why it is presented as such by some. It's as valid as any other method for stabilizing and conditioning raw wood and unfinished woodturnings. It's just a matter, as it is with any "new" method, of separating the hype/misconceptions from the facts.
- Andrew