Thought I would share this find. If you ever used a Patch Worm or weed eater line to clean your airgun, you know how it is hard to feed the line through the baffles of some barrels. I used to use a regular straw in the end of a moderator that worked, but had to use several bar straws attached together (pic above) to help feed the line through a full shroud on my barrels. The bar straws worked but was a pain. So I bought an aquarium 3/16 rigid air tubing. The line slides into the end of the tubing which assists it to the crown of the barrel. This size works in .22 and larger calipers. With .177 I still need the straws stacked.
https://www.amazon.com/gp/product/B0002APYRM/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1