Wow! Maui - I'm jealous. Spent a week in Honolulu years ago, flew over to the Big Island to see Mana Loa, but none of the other islands. I grew up in Fairfax, graduated from Oakton HS and NVCC.
Rate of fire - well let me first tell you that I have not shot competition, silouette or any other, so rate of fire is kinda a moot point. It is sometimes determined by the number of observers. I am not near os disciplined as rdnck or coydog or the other silouette shooters. Thus I have shot 10 rounds w/o using a breathing tube, and have run a patch after every round. I have used a breath tube between shots, and I don't see that anything other than a long string w/o anything trumps my bad shooting. Unfortunately any range is 2 hours away, so I don't get there very often to practice. Rate for fire won't "ruin" the inside of your barrel, just clog it up with powder residue. It cleans up well.
Cleaning - I deprime and drop my brass in soapy water at the range. Bring them home and put them in the vibratory cleaner with ceamic balls for an hour or two. This cleans them well, but doesn't polish them much. I think I'll get some walnut media for my other bin for the Lyman vibratory cleaner. With the MicroBrite ceramic media I use a little water and dish soap. Let them dry well or put in the oven for a while before loading!