Culture - what's the longest time between trips?

[scimor]

My pet chinchilla has not tripped in 16 years, and has recently communicated to me through that odd chinchilla language which incorporates wiggling, squeaking, and hops, that he believes that he's ready for a brain "cleansing", a freshening, if you will, of his outlook. Anyone out there can chime in as to will his long layoff bring back the positives he eroded by using too much and too often in his youth, should he even bother, and, if so, should he go for the gusto with one big heroic dose or maybe ease himself in with a low-dose experiment to re-familiarize himself with the drug's effects? Thanks!