Actually, absence of contradiction isn't proof. If your claim is that agoing is an established word, then I can provide some evidence to refute it:
GloWbE, CoCA and BNC have less than 12 results between them, and all of them are stylistic variants of going.
Across over 1.9 billion words, there are just eleven examples of it.
There appears to be just one example of set agoing. I don't know what meaning you want to convey, but you probably want to avoid this construction, unless you're using it in some kind of narrative.
In answer to your question, though, yes, native speakers will probably understand your meaning if you mean "going", but they're likely to assume that it's a typo, or that you're mimicking someone with unusual speech characteristics.
Since you're asking for help on a language learners' site, I hope you won't mind me correcting other issues with your post:
In English, we use the forward slash as a conjunction (/), not the backslash (\).
Also, thanks so much beforehand isn't idiomatic. You may want to try thanks so much in advance instead.