Removing sealer can be a pain sometimes you can blast it off but not all will come off and you need to use thinners to remove it depending what it’s been done with. If it’s not to bad a light wash might remove the dirt and not damage the sealer , we don’t use a sealer more trouble than it’s worth , we washed a drive years ago that had been sealed , never again it took two days trying to remove some of it it looked like it had come off when wet but as it dried you could see the patched ware it was still on the blocks .