A little goes a long way - I purchased 2 x 4oz bottles from 3M over a decade ago and they are still going stong. It was sold as a 3M cleaning kit with two bottles , wipes and lint free cleaning cloths.

Perhaps call 3M, and ask about Computer cleaning solutions - it was used to clean the heads in disk and tape drives.

I'll ask my local pharmacy about it too - he's used to me asking for strange chemicals that would raise eyebrows elsewhere.