In my experience, unless you are offering someone at least 4 hours per day domestic cleaning its not really worth their while. My girls all do 20 to 25 hours and this is a decent income but still fits in with school hours.
Personally if I charged only £10 per hour I'd make a loss because after wages, employers NI, holiday pay, insurance, cleaning materials, mileage costs, bank charges, admin, etc even if you pay someone only £7 per hour you'll only just break even. We pay more than that to attract great people and keep them.
For office cleaning the cost per hour to breakeven is much lower because you don't usually have so much management and admin time and cleaning materials use is lower, wages are lower and there are no mileage costs. However you will spend time chasing the money so build this into your costs! For office cleaning you can make a decent profit at £10 per hour for 10 hours or more per week but for most we charge at least £12.50 per hour so that holidays are built in to the cost.
Hope that helps
Diane
www.freshlymaid.co.uk