I can’t imagine there’d be many Filipina WGs in the UK. Just too much of a hassle for them and not very familiar either.
Visa requirements and restrictions alone disqualify the vast majority of those that could be interested in the idea. The ones that can travel have better options in asia (Japan, China, South Korea), australia, New Zealand, and the Middle East where they can charge first world rates or close to it as independents.
As has been mentioned above, the unattached ones that can make their way to the UK either as tourists, students or professionals are well off enough to not need this line of work.
Your best bet would be SA I’d imagine.