There might be a market for this with high end consultants or psychiatrists as a more secure alternative to signing an NDA. It'll be something similar to the movie Paycheck
You give the consultant the drug, then proceed to share your secrets with them and get their expert advice on your issue. Then by the end of the day/week/whatever they'll forget everything you told them and your secrets will be secure.
I feel that fundamentally won't work. Experts like that become experts because they are exposed to years and years of clients. One can build useful abstractions without giving away secrets.
I'm sure those experts would only accept jobs like this a very small percentage of the time and only for very large amounts of $$$. Otherwise they're not just loosing out on their expertise, they're loosing out on life
End of the day/week? I assume they'll be detained and watched like a hawk the whole time? There's all sorts of ways to record information that persists even when our memory has been wiped clean. Just take Memento, for example, where the guy tattooed his body with information he kept forgetting, but they don't even need to do that. Pen and paper, talking into a phone, telling a friend the instant you leave, wearing a wire, all sorts of ways to bypass a forgetful pill.
You give the consultant the drug, then proceed to share your secrets with them and get their expert advice on your issue. Then by the end of the day/week/whatever they'll forget everything you told them and your secrets will be secure.