Step one is to keep your drying racks clean and uncontaminated. Use them only for drying well-washed prints and you'll only have the need to rinse them off with water occasionally to get rid of a little dust.
If you suspect fixer contamination, then a weak solution of chlorine bleach (maybe with a bit of detergent to facilitate absorbtion) will serve to neutralize the fixer. Follow this by a copious rinse in fresh water (I run the hose on mine outdoors as chgofrank does).
Best,
Doremus