What Did Rabbi Shmuel Wosner zatzal Call the ‘Invention of the Century’?

The humble bidet.

(According to a nameless pamphlet.)

Here’s a photo to illustrate (Wikimedia, by Deaya921):

Explanation: Not only does the bidet save Torah time (and saliva), it prevents flatulence from later re-contaminating the anus (פי הטבעת).