Thank you Terpe.

I wonder exactly how he can prove "strong social, economic and family ties back home in the Philippines" though? I can only think of letters from his family saying he is needed there and a letter from one person he works for there (it's a small contract though - the rest of his work is just done for others on a freelance basis). Will these be enough? Is there anything else he can do?

My other question is whether he should have an invite from me or not? Others have advised not, on the basis that he might want to stay with me and not go back. They say the application should be purely about him being able to fund his visit and him having compelling reasons to go back home. But you said a sponsor helps greatly? So we are not sure which is the best route to take there.