ALX6004 Alumina Powder
This is the finest aluminum oxide cleaning abrasive for use in cleaning metal surfaces and ceramics of all delicate instruments. The surfaces will be cleaned with minimal abrasion and scratching.
It can be used either wet or dry, with a motor tool or cloths, Micro-Mesh sheets or cotton swabs for hard to reach corners.
Here you can find a link to the Cleaning Procedure of a MS source proposed by John Manura from SIS MS Source Cleaning Procedure.