Depends on what's on them.

It turns out that having a little fat/oil on dishes helps get the whole load clean because of some chemical fuckery I don't understand. Something about the surfactants working better or some such.

So, if it's a little light grease, or something that will dissolve completely (like a smooth condiment), I don't bother. But covid chunks, you gotta get off unless you enjoy digging around in a filter that's clogged and under a puddle of trash filled water