Question
There is a section next to our shed with those white marble chip rocks. Under them is an inch or so of sand and then a weed cloth. A lot of weeds have grown in the sand and dirt that has collected and the marble chips themselves are very dirty. I've removed the the majority of the chips. Is there a good way to clean/wash these chips? And does it make sense put the weed cloth over the sand and then put the chips right on top of the cloth?

Answer
There is no easy way to wash the marble. It may be easier just to buy new ones if you want bright white. You could try renting a concrete mixer tumbler and put the rocks in with water and wash several times but I think that would be pretty time consuming.
As for weed cloth...it didn't work the first time and it wont ever. Weed cloths do one thing...make money for those who sell them. The don't work because inevitably organic debris end up on top and act as soil for weeds on top of the mat. They work for about a year then you have to redo them.