I own several f MS cast Iron Enamelware.  I find one should always hand wash.  They are as close to “stick free” as possible and wash beautifully!  I oil the rim of the pots, and the lids, the part with little to no enamel.  Over time they rust, oiling keeps that at bay.
Anytime they are on sale at Wayfair great to pick up.  If bread making is something you want to try, these are fantastic for Artisan “no knead” breads! Must be min 6 quart, round or oval!  Thanks.