Ketamine is indeed safer than many other anesthetics in terms of the risk of respiratory depression, which is why it is a common choice for veterinary anesthesia. However, it's not uniformly better than more conventional anesthetics. Its half-life is substantially longer than that of propofol, so it actually takes longer to recover from. There is also some evidence that repeated administration of ketamine can produce brain damage, although it's unclear whether this is clinically relevant.

As long as we're on the topic of targeting the claustrum specifically with pharmaceutical agents, I'll point out that the claustrum has a particularly high density of kappa opioid receptors, which are the target of salvinorin A, the active constituent of the psychotropic plant Salvia divinorum [1]. Of course we have no evidence the plant's effects are specifically related to its action in the claustrum.

[1] Smythies, J., Edelstein, L., & Ramachandran, V. (2012). Hypotheses relating to the function of the claustrum. Frontiers in Integrative Neuroscience, 6. doi:10.3389/fnint.2012.00053