personally i would just probe. Its more acurate and safer for the snake.
Popping is perfectly safe if done correctly (just like probing)...and imo just as accurate if not more so...especially with hatchlings...there's no mistaking a male hatchling...Boooing!!!
Lucifer Sam, Siam cat...
Always sitting by your side,
Always by your side...
That cat's something I can't explain...