Try
http://www.m-clean.co.ukI know Rob was quite helpful this way.
Although he insisted on ..
A CSCS Card
Your National insurance number.
Possibily your own public liability insurance.
Safety equipment…i.e. Harness,boots,hard hat, rubber wear,lanyard etc.
IPAF licence
25 page Risk assessment and method statement.
You would need a site induction.
Previous experience of cleaning "industrial" installations would also need to be taken into account.
If you have your own machine that is capable of more than 25lpm that would help also.
Most work is done at night so being nocturnal would be advantageous.