Have you determined what caused the abcesses? Laminitis, foreign object, white line disease, seedy toe etc? Sometimes the abcess can drain better if the outerwall of the foot is dremeled out. It could take weeks to months for the lameness to subside. Depends on coffin bone rotation if the horse foundered and being that you have abcesses on the coronary band, the hoof wall has to grow out to strenghten.

I'd call your farrier and work with your vet to avoid further complications.

My, then 3 yo Oldenburg filly, had a terrible abscess in her left front foot last fall.  It had opened a small hole and began to drain after a few days, but she continued to be quite lame, until a much larger hole opened at the coronary band and it, also, blew out the sole.  Then she was nearly sound.  About a week later, I discovered that before coming out the sole, the abscess had gone subsolar and detached her sole the entire inside heel of that foot.  It was goopy and soft and yucky under there and I completely panicked.  I called my farrier and she wasn't panicked.  She was off for two months, until all the draining was completely done and my farrier felt it safe to cover the sole with a leather pad (since the entire heel was open) and shoe her.  The shoes were a whole 'nother nightmare and fortunately, after 2 months, we were able to ditch the shoes.  My farrier retired in the meantime and I now use a Natural Hoof Trimmer and I LOVE her and what she's done. 

It used to be, vets immediately opened and drained abscesses and the horses usually were quickly sound after that.  Apparently, the newest wisdom is that you can do more damage trying to open them, than in letting them find their own way out, but it certainly didn't work for me last fall.  That whole heel thing was an awful mess.  My farrier was afraid that heel would crumble and she would lose the whole heel of that hoof, due to the tissue destruction and the hole in the coronary band was about an inch long.  Fortunately, she grows a lot of heel and it never did break off until it got to the very bottom.  The vet HAD seen my horse as soon as she was lame.  Of course, I had literally, JUST gone out of town for a week.  The message on my phone from my barn was from just after my plane had taken off for Boston. 

It sounds like your horse may be like mine.  It opened, but closed back up and didn't drain fully.  while I was away, they were not able to soak my filly but a couple days.  I had no problems when I got home, but a week's worth of damage had already been done.

Have your vet and farrier involved...

Stall rest

Get your rubber soaking boot fill with the WARM water mixed with epsom salts and soak hoof everyday...followed with a drawing poltice held in place with a baby diaper and duct tape...

I second Paul.  I've done the Epsom salts soak, baby diaper thing.  It's tedious but it works.

Good luck

It sounds like the abscess closed up and didn't drain completely or there is another one. Most of the time, when an abscess bursts, It is immediate relief. ( no more lameness ) Since it burst through the coronary band, I would tend to bet there is another one at the bottom (sole ) of the heel. Especially if there is a soft spot.

Keep soaking with warm water and Epsom salts, maybe even twice daily. I soaked my guy with Epsom salts and Betadine in the "soaking boot". Then apply a Duct tape boot with Icthamol ointment ( drawing salve ) to draw out the abscess.

Be real consistent and u will get it. It is tedious but u will get real good at making a duct tape bootie!!

My Wife's TB/QH mare gets an abscess in the same hoof every spring.  We treat as follows...similar to some of the other suggestions...

First, 1/2 hour soak in epsom salts and warm water.  Let dry, keep clean. 

Fill a baby diaper with a poultice mixture of 1 part oatmeal, 1 part epsom salt and enough water to make a paste.  Secure this on the hoof with duct tape or vet wrap, and leave on for 12 hours.

Remove diaper, soak in epsom salts again for a half hour.

Let dry, keep clean, then pack the abscess (when it opens) with iodine-soaked cotton balls.  Tape securely.  Leave this on for 24 hours.

Remove and start over again with soak, poultice, soak and iodine pack.

After about 3-4 days, the abscess should dry up and lameness should subside.