Are they worth having?

I'm speaking of ones like:
http://planet.farnell.com/email/cpc/WebOffers/ultclenr.htm

The fact that it loks like a toilet is obviously a bonus. It would be
almost worth it to have dentures just to be able to put them in a
cleaner that looks like a toilet.

Can ultrasonic cleaning damage things? I can see that dunking Grandpa's
1959 Omega Constellation in there is probably not the right way to go.

Daniele