So I would assume that this structure is also valid for any similar verb that can have 2 objects, like < jatlh > (tell, say)

Thus, taking the example “I told you no” (“you” being singular here):

Correct/classical grammar:

SoHvaD < ghobe’ > vIjatlhta’

Here the verb prefix is vI (I--it), agreeing with the direct object < ghobe’ >.

Prefix trick:

< ghobe’ > qajatlhta’

with the prefix agreeing with the indirect object “you”.

"Verbs of speech" are a special case. TKD section 6.2.5 tells us that when using two sentences consisting of a phrase with a verb of speech and a phrase the speaker is saying, the two sentences are treated as completely separate and simply put next to each other, in either order. Thus, what you say is not the object of the verb of speech.

SoHvaD jIjatlhta' ghobe'
ghobe' SoHvaD jIjatlhta'
I said to you, "No."

Notice that the verb of speech has no object.

You can use the prefix trick with verbs of speech, even if they have no object:

qajatlhta' ghobe'
ghobe' qajatlhta'
I said to you, "No."

-- 
SuStel
http://trimboli.name