Jiraiya hides in a barrier toad and the toad hides inside Yomi Numa. Ma and Pa prep frog genjutsu inside the toad and when it's ready, Jiraiya summons a toad beneath him to disperse the mud and push him up out of the swamp, then the genjutsu is used and paralyzes Ay and Onoki, allowing Jiraiya to end them both with Chou Oodama Rasengan.
This is of course, assuming Sannin have full intel and are out of character because Orochimaru and Tsunade wouldn't willingly sacrifice themselves as pawns to distract them, and it's also assuming Ay doesn't decide to just blitz Jiraiya first (full intel works both ways and if the kages knows Jiraiya is the only one that has a potentially threatening jutsu they will go for him first.)