As far the epoxy goes your right on scrape then repolish....marble polishing should take the sealer or haze off just realize if it is "granite" the polishing powder won't polish it but that's not what your looking to do so you should be fine there.
 
As for the slate was it a topical acrylic type of sealer or a penetrating enhancing sealer?We have had the most success using a stratagit (stiff brissle brush) on the bottom of the floor machine with a little weight then use your chemicals and water tank to rinse you may have to do this a few times also use your stand up grout brushes to get those cleft edges.....
 
I wish there was a magic quick answer and maybe someone else has it but for us it has been the proper chemical brushes machine dwell time and rinse..
 
Good Luck
 
Have a good week everyone $$$

--- On Sun, 2/8/09, Don Semi <don@srsdenver.com> wrote:
From: Don Semi <don@srsdenver.com>
Subject: [sccpartners] Black Slate & Granite
To: "Restoration and Maintenance" <sccpartners@stoneandtilepros.com>
Date: Sunday, February 8, 2009, 6:42 PM

Hi all:
 
Have a custy who is trying to salvage a bad job. Two issues. First, although I have stripped wax and excess sealant off of slate flooring, I am looking for an easier alternative than picking away at it. A good quality black slate that had excess Miracle Sealant Seal & Enhance. Unfortunately it appears they did not remove excess. This left the usual milky finish and whitish residue in the clefts. Next guy comes in and tells her that he acid washed it then resealed it with same sealant. (He did  a 200 Sq ft in less than an hour) Needless to say, same result. Question - any new ways to get the sealant out of the clefts without hands and knees work?  am I forced to just really work it?  The second question is black honed granite. A good deal of excess epoxy on seam and it looks like it also was sealed. Scrape off epoxy and marble polishing powder to remove sealant on granite surface? 
 
Thanks in advance for any assistance.

--
Sincerely:

Don Semi
Stone Restoration Services - Denver
Dedicated to the Preservation of Fine Surfaces
don@srsdenver.com
303-249-7909