I have found Earex from the chemist to be better than anything you can get from the vet, and much cheaper (I think its a couple of quid). They usually don't mind it too much as it only takes a couple of small drops and it is very soothing.
But if you cannot get drops in his ears it is going to be VERY difficult.
Believe me, I understand totally where you are coming from - I have a dog similar size to yours (if not larger) and he will not let me do anything to him, if I even start to look at a cut or anything I get woofed at! (and if I persist he gets worse!). Even putting Spot on flea treatment on him is virtually impossible and involves me taking it out on a walk and putting it on when he is distracted by another dog or something!
Would he allow you to put ear drops in while outside on a walk (more distractions to take his mind off you)?
Sometimes it works if you massage gently under the ear first (they usually like that) and warm the bottle in your hand (that way the drops are at blood temperature and not cold going into the ear).
Good luck!