This is to the Admin mainly
You can't work for the full 24 months on a WHM visa. See this on the BAILII website
AK (WHM, maximum 12 months work) Bangladesh [2007] UKAIT 00064 (12 July 2007) and
AG (Working holidaymaker: ‘incidental’) India [2007] UKAIT 00033 (27 March 2007).
The rules say that the person "is intending only to take employment incidental to a holiday, and not to engage in business, or to provide services as a professional sportsperson, and in any event not to work for more than 12 months during his stay"
You can't engage in business, as far as I am aware that means that you cannot be self employed. The work has to be incidental too, and no more than 12 months out of 24. It doesn't seem to matter if this is one hour a week for 12 months or full time for 12 months, both still count as 12 months. Working every month of the whole two years goes against the both the "incidental" and "12 months" requirements the way I have read everything.
It may be worth pointing out too, if Alice Rickards wants to use work experience gained in the UK to help get a work permit, they do not take into account experience gained through working illegally in the UK.