Harbor Freight sells an assortment of brushes of various sizes in a bag. Some of them are perfect for the threaded holes in the cylinder. Some work for the chambers and barrel. There is also a large size that works very well for the gunk between the arbor and the frame and in the hammer channel.
As for pinching caps, I think it is not a good idea. I think it is worthwhile to get the right size caps and if you can't find the right size caps, change the nipples.
I have only had one chain fire but I am about 90 percent certain it came from a poorly fitting cap. It loosened the arbor and I don't shoot the pistol any more.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson