Note the dates; I didnt just hijack your idea.
If you want to work together I would welcome it.
I think its a great idea, however a common problem I find is that some people dont use the internet, not because they cant but because they dont want to.
That obstacle can be overcome, for example by advertising on radio or in print, direct mail to publicly- or charitably-funded employment agencies and the like.
For example, it might be useful to see where these potential users aggregate when they first arrive. Church, known black-market-labor places where a "boss" will come and pick up a select number of people for the day. And go after these places..
A person coming in will probably seek the assistance of close family members, or seek the assistance of a trusted figure (hence my example of Church). Maybe it would be useful to talk with the representatives of these communities and explain to them what you are trying to do. I think they'll be pleased that someone even cares and will have a lot to say about the actual situation and you can use that to tweak it and make it fit..
They're not using the internet? It might make sense that they might not be able to afford a smartphone or a computer and internet access, etc. So I think it'd be good to talk to community leaders.
Good luck..