Hi Mark,
I charge builder cleans by the sq ft, it includes all the spec you have mentioned, it would have to be one hell of a big property to take 22hrs to clean,
I dont know much about these park homes, but at a guess I would say the biggest are about (24ft x 50ft) 1200 sq ft, priced between 90k - 200k.
I really cannot see how one could ever need 22 man hours to clean.
I would charge £145 - £168 per unit of this size, If I sent two staff to clean this size of unit, I would expect it to take no longer than 4hrs each maximum.
You would have to charge alot of money for each unit to make a profit if they take 22hrs to complete.
Ive carried out new build cleans for 7000 sq ft properties being sold for 2.5 million, attention to detail is also a must on these.
regards
Paul