wiping off a nice new plastic seat is obviously far easier than an old wooden seat with cracked paint.
-- Perhaps shellac wd work? Seems cheaper & easier than new seats -- as long as it's non-toxic.
Shellac won't affect the perception of an old cracked wooden seat. And unless you're willing to put on several coats of clear coat with sanding in between, the uneven texture from the wood underneath will still trap dirt.
Home Depot has a decent selection of toilet seats in the $5-20 range. Seems like a worthwhile investment, given that we probably don't need to replace all of them anyway.