if Jiraiya has Bunta jump and use super fire blast, will Deidara have the time to use C4?
And if Deidara uses C4 and Jiraiya has Bunta use super fire blast on it, won't the gaseous bombs disperse away from Jiraiya? Guy when faced with the Six Tailed Slug's acidic gas, he simply used the flaming heat of morning peacock to disperse it. Jiraiya doesn't even have to know that it contains corrosive gas, he can just blow it away literally to try and push the blast away from himself as he would be expecting an actual explosion.
Either that or he sinks the giant Deidara with Swamp of the Underworld. the Swamp is meant to sink giant enemies and if it explodes in the swamp it won't have any effect. as the adhesive chakra will hold the gaseous bombs in the swamp.