I rinse em and give the baskets a clean with a brush once a day to unblock the holes. Also daily I give the group a clean with the supplied brush and give the grinder a brush out with a pastry brush.
Once a week I use "Cafetto" cleaning powder to soak my handles and baskets for 10 minutes (luke warm water & 1 scoop).
I use this for a weekly backflush too as well as giving the grinder hopper a wash in plain warm water.
Cafetto is really effective and easy to obtain. Im sure you would be able to get it from any of the sponsors here.