Hi, I also run a small cleaning company in Surrey. I would ride on the side of caution. I think recruiting is the hardest part and sometimes it is really tempting to employ the wrong people because you are desperate.
I have in the past employed a polish lady. She was fantastic, but she was my neighbour's niece, so I knew she would be ok. However, when I have placed adverts in the paper I do get a lot of calls from Polish people, and I always record and make notes of everyone I speak to. On my last ad I got calls from the same person, giving different two names and contact numbers, another person who I actually went to meet and it turned out that she lied about her address. I spoke to my polish lady and she said that I should be very careful, as there are quite a few scams going around. It is a shame, it has put me off. I was also about to take on a very nice lady (British) and although she had glowing references, I still checked them out, and what I got over the phone was very negative. Lucky escape. I simply don't think its worth the risk, unless someone checks out completely.
You have probably tried several of these methods but schools are a good target, mums wanting to work around school hours, also your existing cleaners are often a good source, doing leaflet drops in local authority blocks in the areas that are close to where your clients are. Good luck.
JulieG