If a vessel only held cold food, never hot, but was washed in the dishwasher, does it need hagalah for pesach? Or nothing?
Is your minhag not to use any year-round cookware for pesach, or do you kasher some things?
Definitely better to kasher the vessel if you can. In theory there are arguments to be made ... but the standard practice (from what I know) is to kasher everything. A few hundred years ago, Ashkenazim would do "milui v'irui" (three-fold 24-hour soaking) for their drinking glasses, but that's not recommended these days; if the vessel can withstand the heat, kasher it; if not, don't use it. (Sephardic practice is more lenient, check with your local chacham...)
But sure I'll kasher things. Occasionally I wimp out and bring it to my shul, where they do large batches of kashering with their professional-grade kitchen. (I'd think the fact that most shuls offer such a service is an implicit statement that they have no custom against kashering.)