This is the only supply of .1u I could find in the UK. Works fine. Think the reason I couldn't find it initially was because it is advertised as 1/10 micron, that's the same as .1u
RS PRO Grey Diamond Paste 1/10μm Grade , 10ml Bottle | RS Components
uk.rs-online.com
RS PRO Grey Diamond Paste 1/10μm Grade , 10ml Bottle | RS Components