The article’s 3rd section (“Getting a measure”) is explicitly about alternatives to self reported vividness of experience - citing use of ocular rivalry effect, measuring dilation of pupils when imagining a bright light and sweat responses to a scary scenario. I agree that it’s a difficult thing to make sure people aren’t just experiencing similar things and reporting them differently but there does seem to be effort made to design experiments around differences in how participants form descriptions.

“Sim sala bim” is one you see a bit in the Nordics, popularized by a Danish magician with the stage name Dante. Gibberish definitely does help remove the magic words from what the audience knows a bit.

According to TVTropes (Gratuitous German, AoaB examples page) it looks like they lean less on German names and more on nouns like Angriff (attack) and Leidenschaft (passion). Japan particularly seems to like choosing German as the gratuitous foreign language.