A zapper is a series circuit. The resistance between wrist straps made with no resistors in line and the gray fabric, which is tiny silver wires VS copper pipes covered in wet paper towels, is virtually nil (in favor of the wrist straps).
So, you got 50 or so ohms give or take between each zapper to body interface and you have a body of maybe 1,000,000 ohms resistance.
You are arguing about the difference between 1,000,000 ohms and 1,000,100, or less.
To make zapper straps without resistors, you need to order at least 1,000 and pay up front. Some low volume makers can't afford that and therefore trash people that offer them by saying the concept is flawed.
To me, I'm NOT going to tie up my hands holding a pair of pipes for an hour a day, maybe others will, but not me. The ONLY way I'm going to use this an hour a day is if my hands are free to do other stuff.
Just my opinion, your mileage may vary.