not much, as I don't read German or Dutch

Sorry, I was in a hurry, as I'm about to walk out the door to help a client, ... roughly, the German says:

"Ass's bridge is originally (after Esiler Dictionary of Philosophical Concepts) a 'logical comparison of an illustrative figure'. Accordingly, J. Chr. Günther 1735 Ged. 462, 'a freshman who walks on the bridge of asses'. Adelung "difficulty which confuses the ignorant". Also in a Ger-French dictionary: "pont aux ânes, a measly aid for the ignorant".

The Dutch mainly cites forms in other languages. The French definition is roughly:

"a simple something for helping obtuse geniuses"

It seems that the European languages use pons asinorum (in the local vernacular) as an aide memoire or mnemonic as your Dutch correspondant suggests.