Hi Rob,
I dealt successfully with this problem on the dented soft dome cap on 13” JBL bass driver. I can’t say for sure whether it will work on the smaller dome of a tweeter, but worth a try. For what it’s worth, I tried scotch tape too, to no avail.
Try a vacuum cleaner hose. Open up the slider on the top of the hose to reduce suction pressure. Use the nozzle attachment for tight spaces, which concentrates suction to a small area. Approach carefully of course. Worked like a charm for me.

