Nest boxes

My two girls havnt started laying but arnt that far off now, i have there nest box in the house full of straw ready for their use.   How often do you totally clean out the nest box if they arnt pooing in there, just laying eggs, once a week, just would like to know how everyone else does it.    Nicky

we usually do a scrub down monthly:
we have newspaper down under  the perches which gets changed every day, but the straw in the nest box gets done when it looks like it needs it (actually, probably once a fortnight).
 
(and live in hope that one day NO chickens will sleep in it!