i've done mine anywhere from 5 to 8 days and all have been fine. i'd say i prefer about 6 or 7. i usually prepare mine on a friday and the following weekend i rinse, leave in the fridge overnight, then smoke the next day. so to answer your question, 7 should be enough, but you could leave it a little longer if you want.
*A Texan transplant*
UDS | Blue Weber Performer Platinum | Chargriller Akorn | 22.5 Weber OTG | WSJ Gold | Mini WSM | Maverick ET-73 | Blue Thermapen | Maverick PT-100 | Gasser(charcoal chimney starter)