can an ex-refugee of HK apply for Domestic Helper visa via sponsorship?

Hi

So i had a friend who was a refugee in HK and while he rented a room in my flat he took great care of my mother and my kids,of course without any pay as refugees arent allowed to work here. and he took care of my family as if it was his own family so he didnt require any pay. So now hes gone back to his home country but my kids miss him so much and I want to sponsor his visa as a domestic helper.
My question is, do any of you know if he can get DH visa easily as he was once a refugee here in HK? he never committed any crime and his record is perfectly clean. Whats the procedure to apply for his visa and how long will it take? I have a 1 yr old daughter who literally grew up in his hands and shes being uncontrollable by us as he was the one who handled her the most and took care of her. Please someone answer as soon as possible how I can apply for his visa and if it will get accepted or not. Your answer will be highly appreciated.
many thanks

Unlikely. He returned home so not a genuine refugee, plus he was working here (still counts even if he wasn't paid). Immd will assume he is just looking for a way back to Hong Kong, and perhaps trying another bogus asylum claim.