That was my idea as well, but then again. As the post below, the Gods are fickle. They may not want to inhabit the characters afterwards.Just treat it like a voluntarily failed save, I guess?
Yes, but would they stay rejected?Honestly, I'd go with the interpretation that the gods are fickle and once rejected would go with someone else. Since a successful save only blocks that specific god for that specific character, the character can get a different god and the god can get a different host.
I might end up saying they will have to go through a certain test to see if the characters are "willing" to accept the gods as they have already rejected some of them. DC 15 Wis - if they fail have some negative effect untill their next rest.