>>5
Funny. 垢層 is 「クソウ」.

Cruft is also used for any sort of junk, or something which is old and works strangely.

I have a directory called ''random-cruft'' where I keep text files with ethernet addresses, phone numbers, コピペ, quotes, scripts, five-line C programs, and other things that don't belong anywhere else. They would clutter up my home directory, but I want to keep them for some reason. So they are "cruft".