I wouldn't put it in the dishwasher - the high heat will likely soften it and it might wash right off or smear. I'd hand wash it instead. The glaze coat on most dishwasher safe items is usually fired on in a kiln and I don't know how to do that so I can't advise on that. Most products that aren't meant to be finished in a kiln aren't really dishwasher safe. There are some that claim they can be baked in the oven to make them dishwasher safe but I've never used them in one as I don't have a dishwasher (current kitchen space won't let me have one).