Mike, always stay in the driver's seat and never let your customers dictate your profession. One of my competitors only does bee removal at night, been doing it that way for many years. They say they do it at night because all the bees are there and they will get all the bees. This is of course is 100% nonsense! I've spoken with a handful of people who used them over the years and questioned those customers about bees that were left behind.
Every customer of theirs I spoke with had some bees for at least a week after the removal.
I never under any circumstance tell a customer they won't have any the following few days to even a week. Heck, some bees from just about any hive domestic or feral don't make it back in on a regular basis. They work themselves to near exhaustion and some just rest outside on a branch, side of the hive etc... if they survive the night they go back in the next day if they have the energy.
The product in question is more expensive than bee quick so I don't see the point.