Yeah, I second what Clean 'n' Tidy said.
Arrange one day to do interviews and try to pack in as many people as you can - you'd be surprised how many people won't bother turning up. :
At the beginning of the interview ask them to fill in the application form and make further notes for yourself during the interview or immediately after - your preference. This is very important because you'll be amazed how quickly you can get confused between different interviewees at the end of a long day.
Such notes could be based on a rudimentary scoring system, i.e. Level of English (difficult to tell on an application form), whether they have made an effort with regards to their appearance (it may 'only' be a cleaning job but it can tell you how much they want the job), their perceived knowledge of the correct cleaning methods, whether they require time off during school holidays, and so on.
Interviews are a good way to go because you never know who really fills the form in, an interview can often sort the wheat from the chaff!
Hope this helps... And good hunting!
Regards,
Darren.