Goes on the end of a cleaning rod and holds a patch.
Appropirate sized, rod, patches, jag, solvent.
Any .30 caliber cleaning jag will work- and yes, it is a very common item.
Unloaded
cotton, rod, jag, cleaning solvent.
Jags, whether brass, plastic or other material are a slightly under caliber sized tool that is ridged to hold a patch. The patch is placed over the jag (most have a small point that you can puncture the patch with) and inserted in the bore. As the patch over the jag is almost exactly the size of the bore it makes better contactwith the lands and grooves. It will quickly and efficently remove fouling and grime. A fitted jag reduces the number of trips a patch must take down the bore and it reduces the amount of time scrubbing with a bore brush. This will help extend the life of your arm.
Use the proper size bore brush, jag, cleaning patches, solvent.
Gun cleaning kits can be purchased online at Amazon, Walmart, and Optics Planet. The price of gun cleaning kits ranges from thirty dollars to over 100 dollars.
Kerosene, Alcohol, pear oil (Amyl Acetate), and ammonia are the main ingredients which are best for gun cleaning purposes.
unloaded.
NO! CLP, yes. CLR is a strong acid that is meant for cleaning toilets and sinks. It will corrode a gun.
It sounds like you're talking about the eyelet which goes at the end of a gun cleaning rod. A cleaning patch is inserted through the eyelet, and the whole thing is run through the barrel, in order to swab out carbon deposits and other dirt, dust, etc.