So I had a tonn of used carts and decided to try and clean them. Took the fill holders out of my 401 and Npro carts and just used the whole 901 carts, then let them soak in boiled water for a while, swaped out the water when it wasn't as hot, let them soak some more, put them in a collander out in the sun till they dried and seem to work very well. The filling seems a tad denser but works well. 
