Any problem with toggleing hard drives by power?

I want to literally toggle -on and off- two different drives on my computer. I'd like to have 2 toggle switches I'll be connecting to the power of each and adding to the side. While the computer is off, turn one on, and the other off, and the inverse for the other. Is this a problem "port wise"? Of course the computer won't connect the drive as there is no power, but will it create any errors?

I'm fully aware there are many ways to dual boot with software/hardware but this is a different project that I want everything completely separate. I'm sick of pulling the drive and power every time. It's further confused that one is IDE and the other is sata or I'd consider a KVM type switch. Thus, a power toggle.
Or also open to a better idea.