Neil ............ i know as well as anyone the HWE is more thorough and deep rinsing but that cannot be used to full effect on bitumen backed carpet tiles .............. surface cleaning low moisture method is needed and Charly does that

I have used Charly pads and improved on areas cleaned with TM .......... any second pass will improve to a degree, which ever way round you do it. Surely that is why many operators utilise bonnets after HWE to speed up drying times, this can also remove soiling and marks missied by first clean !!
Only other bonnet method i would employ would be Texatherm, seen demo before and loved the system .......... new layout is far more efficient looking as well.