Bore Snakes are great (I have several for both rifles and shotguns), but for deep cleaning you'll come up WAY short if that's all you use. I just don't believe you can get all the fouling out unless you use some sort of solvent and even a brush from time to time. I also like using the Otis system - it's expensive but very good as all the cleaning is done from the breech to the muzzle and uses a cable instead of a rod. This makes the whole system extremely portable (it fits in a pocket). Keep this in mind, there are aggressive solvents and non-aggressive ones. Hoppe's is a non-aggressive, and you can leave it in your barrel overnight if you want (I don't think that is necessary, though.) Barnes and Sweets are examples of aggressive cleaners, and you shoudn't leave them in for more than 10 minutes or so. (Ronn) If you use these, ALWAYS finish with a light oiling as per the instructions. Once, I cleaned my barrel the night before a hunt and, after running a few dry patches through it, I thought I'd skip the oil. The next day, after hunting, when I unloaded my rifle, the bullet that had been in the chamber came out blue - I guess the slightest bit of solvent that was still in there started reacting with the brass of the case!
It would have been better to finish with the oil and then run dry patches through right then or just before hunting.