Runoutofideas, I'm not a health professional but I work in the NHS. The NICE guidelines on this topic, which are based on the BEST AVAILABLE EVIDENCE, and which were published last year, say this:
"The following treatments are not recommended for the management of OME: antibiotics, topical or systemic antihistamines, topical or systemic decongestants, topical or systemic steroids, homeopathy, cranial osteopathy, acupuncture, dietary modification including probiotics, immunostimulants and massage.
The persistence of bilateral OME and hearing loss should be confirmed over a period of 3 months before intervention is considered. The child?s hearing should be re-tested at the end of this time.
Children with persistent bilateral OME documented over a period of 3 months with a hearing level in the better ear of 25?30 dBHL or worse averaged at 0.5, 1, 2 and 4 kHz (or equivalent dBA where dBHL not available) should be considered for surgical intervention."
The full guideline is here if you're interested.
So not only are you not being unreasonable in wanting to delay, it appears that the evidence agrees with YOU, rather than the specialist.
The NHS is supposed to follow these guidelines. Private care doesn't have to. Have you been offered the option of waiting?