Kim -
I'm not sure what methods the Copenhagen museum uses to clean coins or what they do - if anything - about
bronze disease. Many of these institutions use rather strong, large
scale chemical soaks because they are quick and not labor intensive, whereas collectors tend to go a slower and more methodical route. So I'm not sure how much
help they will be.
Also, you might not want to wait two months or so before dealing with your coin.
Bronze disease accelerates when the coin is out of the ground and exposed to air and humidity - and BD can get much worse pretty quickly! It's rather amazing that it took 17 centuries for that coin to reach it's present state but how quickly things can change in a matter of weeks as fat as BD is concerned.
I'd suggest either contacting the museum within a few days or taking Kevin's advice and ordering some
Gringott's BD Killer. It's inexpensive, very effective, and a bag will last for many years.
Tony