airwave45, are you aware how different accents can lose tone over the RTF? This means that using "impeccable RTF" - or standard phraseology, is crucial to be understood. A Mancunian accent (and other Northern areas) have to say "too" and "tree" as "two" and "three" actually sound identical to the other end. Northern Irish also have a similar problem with these numbers, but also "seven" and "zero".
If you know that your accent has a potential to be misunderstood, then using the ICAO standard phraseology may sound "entertaining" to you, but I talk from first hand experience that it is imperative for safety reasons.