Ways to arrange homestay or language exchange with families for bilingual kids?

I'm raising a young child in Japan and would love to help them grow up bilingual (Japanese/English).

I’m considering two possibilities: • Finding a family in an English-speaking country where we could do a parent–child homestay (ideally with kids around the same age). • Hosting someone in Osaka for free accommodation in exchange for spending time speaking English and playing with my child.

How can I find trustworthy opportunities like this as an individual (without going through big agencies)? If anyone has experience or advice, I’d really appreciate it!