It depends on caliber. For the Otis, you need the special small size patches that has the cut out on them if you want to use it on a .22 caliber weapon like an ar15. I really like the otis kit and have been buying 1000 patches from Amazon as well. They are not overly expensive. I get the normal/universal size patches and the small caliber patches. However, there is no such thing as having TOO much patches. I have small size caliber square patches as well as normal square patches. I used all of them. The otis patches are really good for absorbing the oil / solvent from outside of the firearm while cleaning. For the barrel, the patches work well if you use them right. However, as the caliber gets smaller, I found the otis patch is not quite easy to use unless you properly install the patch on the cable. I found it makes cleaning rifles really easy. I don't use the otis patches/rods for pistols, though. I still use the old rod system on them.
However, my opinion is to be careful using the otis patches. I have heard of a few folks using it out on the field, and the otis patch come undone and get stuck in the barrel. Unless they had a rod to push it out, it was a done hunt or range trip. During my cleaning, I never had the patch undone in the barrel but I did once get it stuck in the chamber of a ar15 and had to push it out with a rod. I was very fearful that I might have dinged the chamber. For me personally, I carry the otis pack with me on a range/hunt trip, but I also have the boresnake in it to use in case I want to give the rifle a quick clean.
To answer your question, you can use whatever patch you want. The otis cable has the same threads as most brushes and the kit you got has the hole cutout to insert a patch if you wish or install the otis patches easily.