From personal experience with timber mate and similar styled products. The use of these items with too much water can and has caused joined wood to swell and split. Joined timber does not really do well with lots of water.

The consistency of the timber filler you want is like thick custard, slightly thicker than a thick shake.

Just be careful with water around holes as well....it can cause swelling and if there are veneers and or laminates at play they can even lift off.

Honestly, I did this once in the past.....leave the body to dry for about a week. I wedged a sanded down end of a guitar pick into the crack....used a toothpick to apply some good quality glue....like Tite Bond.....original or 2...not the exterior one as it is waterproof and will not allow you to clean up.

Then I used ratchet straps wrap around the body to pull it tight. I put waxed paper, grease proof paper, over the seam of the glue. Then put some small piles of business cards under the metal pieces of the straps to stop any marks.

I used three straps all wound around the body....I have also seen strips cut from bicycle tyre tubes....stretched and tied or pegged to secure them.

I left mine for about 2 days like this.

Just got up and checked it....and you can see the change in grain between the two pieces of wood....but no crack. That guitar was re-joined 5 years ago.

I wish you luck....you will be fine....short of having to split the body and re-glueing it.