I just finished my house (1600 SF). I am a 68 year old female and I did it all. My grout is a light sandstone & was so stained and dirty looking (esp in the kitchen). Now it looks like I have new tile for less than $150.00. My two year old grandson has already spilled a strawberry drink on the floor and it wiped up – no stain!!. I spilled some olive oil & same thing – no stain. WOW I can not believe how great this stuff is. THANKS for a great product that is economical, easy to apply, and looks great!!!