The phonetic alphabet is often used on amateur radio to spell out names and callsigns more clearly, especially when the clarity may be poorer. However, there are cases where I simply forget certain parts of this - in this case, is it ok just to use any old word in its place, or would this just lead to confusion?
Part 97, section 119 covers this. "Use of a phonetic alphabet as an aid for correct station identification is encouraged". Most everyone has settled on the NATO phonetic alphabet, even though its elements have varying numbers of syllables (one to three!) and aren't comprised exclusively of trochees http://xkcd.com/856/.
To put this another way, if you make it difficult for another station to understand you, they're not likely to want to speak to you.
It's not uncommon to use other words in place of the standard NATO Phonetic Alphabet. For example, my callsign is K7FOS, and I typically say Kilo Seven Foxtrot Ocean Sugar after saying the NATO style because it can often be easier to interpret "Sugar" over "Sierra".
Use whatever works in order to get your message over the air effectively.
The TL;DR; answer is No.
The slightly longer answer is still No! - and listening to any pile-up will show it is not the case.
As an example, QRN, QRM and QSB are often referred to as "Q R Nancy, Q R Mexico and Q S Baltimore respectively (not November, Mike and Sierra)...
The point of any "code" is to make sure the recipient understands the transmission... and the advantage of the NATO Standard Phonetic Alphabet is that most (if not all) operators (should) know the letters, which is especially important when dealing with non-English native-speakers.