"The children should be treat equally." or "The children should be treated equally."?
Weirdly enough, the correct word is actually "trut". Click here for an explanation.
Don't agree with that tbh, and I've never heard of that website.

It's the latter in that situation. You'd have to rearrange and rewrite if you wanted to use treat and change the tense e.g. "Ensure you treat the children equally".
Why on earth would you use treat in that example?!
Just because it's from local dialect, doesn't mean it doesn't exist as a word. What was once correct may not be accepted now and vice versa, but words, phrases etc may be retained in a certain region despite being archaic.Treat
Etymology
From Anglo-Norman treter, Old French tretier, from Latin tractare (“to pull", "to manage”), from the past participle stem of trahere (“to draw", "to pull”).
tret [trɛt]
n
[from Old French trait pull, tilt of the scale; see trait]

I'm not using it as treet (phonetically spelt) though, but tret - ie a different word. Think of meet and met.
On another note - spoilt or spoiled? spelt or spelled?![]()

"The children should be treat equally.
treated is both the past simple form of the verb and the past participle.
But if I were you, I'd keep my grammatical opinions to myself.