Not sure what you're insinuating, Mr Gourlay, but I started in c/c when running a substantial contract cleaning and grounds maintenance business, to provide an additional service to clients.
This was in 1983/84
Following divorce I disposed of the business and amused myself for a couple of years, returning to c/c in 1989 setting up a couple of relatives.
In a moment of madness, I decided to take up the tools myself, when approached by a lower priced, but aggressively marketed business.
That was absolute hell, due to the high volume of work, compounded by my inability to compromise my standards and still get through the work, but it was convenient at the time.
The only 'shortcuts' I used were the ones I still use and are probably used by most experienced and competent cleaners,eg, Feathering carpets, Being fastidious about prespraying and agitating almost everything.
There is also the confidence and experience factor, which probably give an additional edge, by knowing when to 'move on'
OK
ROB M