There is also the issue of encapsulation saturation, where after multiple VLM cleanings, the amount of residual chemical build up to a point of causing more wear on the fibers. That's usually why they refer to vlm as an interim cleaning method. Each method has its place and pros and cons.
My concern is guys going to clean residential cut pile and because it looks decently clean, they immediately go with VLM and don't consider warranty issues with carpet. I have personally known mill inspectors to come out because of issues a customer had with a recently new install and mention voiding the warranty because of the VLM method was used. I have even declined a job because The home owners had the carpet dry cleaned (vlm) and then wanted me to steam clean the carpet before they had an inspector come out.
I have to say that I see most warranty issues related to the materials used in the manufacture of the carpet. Mostly delamination from using a poor glue resin in the backing of the warp and weft. Most other issues are from poor or improper install. Cleaning the wrong way or using the wrong chemical comes in dead last.
I brought up the conversation to help bring attention to making better choices with what cleaning method to imploy and when.
