When knocking out the elemental. Short is with your taming tools (rockets,cannon) etc. Back up a bunch till it goes into rock form then shoot a arrow at it to wake it back up. Use the time in between disguising itself and waking up to organize yourself or your team for the next attack of cannons.
It's a bit silly that kibble tames it a lot better than rocks or sulfur because even in the dossier it says that it lives off of absorbing nearby rocks and minerals. So mabey they should make it so you have to feed them a rare mineral like obsidian what if they made it so you could tame one fast and with high effectiveness by giving one a few hundred or few thousand obsidian . or what if there kibble was made out of a combination of ores and minerals .