Been doing "offer. refused? wait two weeks. refused? wait another two weeks. refused again? wait a month." with mine. He's been caving before the "wait a month" stage but I'm seeing a lot less hunger activity from him.
Pretty much just been playing it loose and peeking in on him before bed. If I see him out and about a few nights in a row, I assume hungry and offer one to him. That's been working well for us.