About: http://webisa.webdatacommons.org/84321835

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	OK, first thing to try is an abrasive emulsifying pad (3M or similar) choose the white one as this will not harm you tiles, add some water and a mild abrasive cream cleaner like Nanoscrub and see if you can scrub the cement/grout off.
http://www.w3.org/ns/prov#wasQuotedFrom	tileandstoneblog.co.uk