http://www.rrdvegas.com/silencer-cleaning.html

Not satisfied with the "Dip", The author explores a bunch of different readily available options for suppressor core pre treatment and cleaning.

I personally put a very thin coat of dielectric grease on the outside of my Monocore which keeps build up to a minimum, prevents the core from getting stuck inside the tube, and allows me to pretty much just wipe everything off with a paper towel or some Q-tips. That type of grease is available at most auto parts stores. It was recommended to me by the guy who made my 22 suppressor (not a tiny shop fyi) and I've been using that for several years