Obviously don't wash them. Keep them in a dark corner. I find rotating a different end of the box to elevate once a day fine. (You don't have to overwork at every 6 hours).
Write in pencil the day laid so you can keep track. If possible, write the breed of hen/rooster as well (example Cream Legbar/Barnvelder...CL/B).
Avoid treating the laying hens with de-wormer or other meds (which I doubt you are doing).
Make sure your hens are on a good feed with all vitamins and minerals, and obviously healthy.
LofMc