Ok, found it in my seminar notes so I either took it during the annual seminar given by our vets, or checked the info through the vets for validity.
The gist of it was: What is the efficacy of giving the injectable form (not paste) of Banamine orally? Reason: to avoid the above mentioned infections associated with IM injections/Banamine injections.
The answer was that given orally, the injectable form is just as effective as giving it IM.
IV is still the preferred method for immediate/urgent need, however in light of wanting to avoid IM injections, orally was perfectly acceptable.
Was told it tasted nasty, however when I had to give it to one of the rescue donkeys she only pulled a mild face about it.