Dashing over painted engineering brick

Hi I am wanting to get my shed dashed the same as house, the problem is how to remove paint to let the dash bond with the brick.
I've tried wire wheel in the grinder it just seems to melt the paint.
Tried power washing this has only worked on the joints.
Tried flap discs its eating them.

Am I going to have to buy a compressor and needle gun or any other options.

Thanks in advance