In order to draw out the staining substance that has been absorbed into the stone an absorbent material needs to be applied to the stained area. This process is referred to as a poultice.

There are several premixed wet poultice products available, as well as powder poultices that only require the addition of water to activate them. They are more convenient and safer to use than formulating your own stain remover. These usually can be purchased at a marble or tile store. I highly recommend that this type of product be part of your stain removal kit so that when a staining situation does happen you can address it as soon as possible. Make sure that the product you buy is compatible with the stone you intend to use it on. Example - some products will say that it is not to be used on some types of stones, read the label thoroughly and do not just take the word of the salesperson for granted.

Poultices are more effective when plastic is placed over them and taped down. This prevents the poultice from drying out to quickly, allowing the chemical to work on the stain. The poultice should remain covered approximately 24 hours, then the plastic removed. If the poultice is not dry at this time it should be allowed to air dry so the staining substance can be drawn into the poulticing material. When poultice is dry remove using a wooden or plastic spatula and rinse well.

The stone may have a dark damp spot where the poultice was, this may take a day or so to dry in order to determine if the poultice has worked or if another application is needed.  Some stains require a few treatments. A good rule of thumb is...If after two applications the stain has not changed it may be permanent or it is not responding to chemical and at
this point I would recommend that you call a stone care professional.

It  has been estimated that approximately 85% of the stains in stone and masonry materials can be removed successfully and the remainder will either lighten to one degree or another, or they are permanent.

Do not wipe a wet stain to pick up the solution, this may spread the stain.

Use an absorbent cloth or paper towels to blot it up.