Who ever "Dual Wands"? (for those unaware: Dual Wanding is employing two wands off the same machine)

Now, I understand the logistics, however, personally I would never do it. I recall a few years ago, a operator stopped by and I had an opportunity to "feel" the vacuum from both hoses as he cranked up his machine. He even remarked that he only had used that feature once or twice but has not used it since because he did notice a drop in his extraction performance overall.

Back in the 80's we even tried it on our systems and noticed a huge drop. That was the end of that experiment!

Another failed attempt which we dropped was the internal psi hose inside the vacuum hose. (commonly referred to today as: "hide-a-hose")
Problem was it would pre-maturely coil up inside the vac hose and thus decrease the cfm/airflow big time. Further, it would collect debris, etc like crazy.

In the end, however, it is always interesting how someone out there (re-) introduces this so called feature(s) on the backs of the unsuspected purchaser, then discontinues it because of complaints and failures some time later! Guess there is a market for just about anything!