Dead on!
There is a reason my most in office systems reccomend follow up home bleaching to achieve the best results. Think about it
Bleaching in a nutshell is a function of bleach strength and time applied. Balance those 2 with patient comfort, and you'll get the best results
FOR THAT SPECIFIC CASE
On a side note, I notice a majority of the time that my patients that ask me about bleaching are the ones whose teeth are already a light shade to begin with (Vita A-2 or lighter), and those are the ones where I really need to take the time and give them a REALISTIC expectation about what bleaching could do for them, since most of them tend to think that their teeth are "awfull", "gross", "disgusting" or a variable host of other self depricating adjectives!
Without taking a few minutes of time to explain to this population, you'll end up with a patient who in all likelyhood whitened a few shades to B-1 or lighter, but STILL thinks their teeth are one of those great adjectives! Suprisingly enough this population tends to be females between the age of their teens to 40's
The same demographic that makes up the largest consumers of dental cosmetic proceedures!