Hi, the kids keep dripping soap blobs all over the marble counters we put in our master bath 18 months ago and now we have a few dark spots where it has sunk in & stained. What should we use to re-seal before it gets worse? I've read a lot of product reviews that say things work great on granite, but not so much on Marble (like the 511 Miracle Seal...supposedly more granite-friendly).

Thanks!