how can I clean this surface of cv grease

[omodos]

Finally managed to find clamps from here

www.hcl-clamping.co.uk/‎

When I remove old loose inner clamp I’ll clean the surface of the boot where the new clamp will come into contact with boot, this is easy.
But how am I going to clean the inside circumference of the boot at the small end shown in pic(without taking off boot)? I can clean the shaft no problem. If I can’t clean this inner circumference no matter how tight I clamp new clamp on the bellow may still move left to right which is issue I have. Any tips much appreciated.