I am not sure how thick/rugged an AMT tweeter is -- try to track down AMT and ask them? Ribbons are very fragile and it is easier to replace than clean them. Most of the time cleaning leads to destruction leads to replacement anyway... But I am not sure exactly what AMT uses -- it used to be a heavier corrugated material that you could brush,
gently...
Old experience follows, I am no longer working as an audio tech and have not in years.
The old Infinity EMIT/EMIM and Magnepan's panels (not the ribbon tweeters) could be cleaned using a camel-hair make-up brush as
@restorer-john suggested. That was always my "go-to" solution in my techie days. An air blast or vacuum would easily destroy the membranes if too strong, and since the airflow is almost impossible to control, well... Some ESL panels could be removed and hosed off (gently!) but most manufacturers IME say to just ignore it until they start arcing, then rebuild/replace.
FWIWFM - Don