I've recently been noticing some patterns which look like two repeated past-tense verbs, but I think which indicate a command rather than the past tense. For example:
さあ、行った行った。
"Get along with you!"
I also noticed in the Baseball manga "Major" the following, which was called over a loudspeaker:
入った!入った!
But I'm not sure what it means, or indeed if it is a command or baseball/sport-specific (it was at the start of the chapter and I'm missing the previous volume so I'm not 100% sure what the context is.)
If both of the above are commands, are they roughly equivalent to さあ、行け and 入れ!? Is 行け! more assertive than 行った行った!?
Can this pattern work with any verb, e.g. さあ、食べた食べた! or is does it only work for a few?