Antifoul Removal

[Antipodean2]

I had my hull blasted with ground glass about 7 years ago, the result good all old foul was removed and taken back to the fairing . No moisture or little was found and after drying for a week , epoxy resin was sprayed the 2 coats high build epoxy International protect then Antifoul .
I have just slipped and found I had a build up of Antifoul and my hull was not smooth due to Antifoul coming away.
I would like to inquire what is the most cost effective way to remove old Antifoul.

The options I have is to re blast the hull or planing, I have tried sanding but a dirty and long job for average result.

Any one had success with these methods or any other ideas