Washlet is quite common in Japan, and accoding wikipedia jp, washlet type cleaning toilet has 60% penetration in all Japan households. Today I happened to find their online ad in popular weblog buzzmachine, where TOTO, the manufacturer of washlet, seems to penetrate into US. Their website communicates clearly the benefits of washlet and is well- organized. Mention about hemorrhoids, however, found only in the questionnaire section, which in my opinion is but the key message to be delivered. Maybe they have no evidence to support the effects on hemorrhoids. Many people around here believe so around here.
Here’s washuretto community inside orkut.
Somewhat related article at boston.com: Japan High Tech “Washlets” aim at US bottoms.