I use a length of fishing braid with a small loop on one end
Then feed it down from the mussle end.
If you have a silencer on just use a drinking straw to to get to the braid past the inturnals
Then baby wipes dried and cut into about 100x50mm strips
quick sqirt of wd40 not to much pulled through till they come out clean
then some dry ones to remove any of the wd
job done
CHEERS
GARRICK.