This sounds like a nefarious question but it's really not. I have a work laptop and I need to get some personal planning done after work tomorrow. Naturally I don't want to carry 2 laptops or run the laptop on the internal hard drive for personal use, but going back home and out again is very inconvenient. So my question is - would dual booting via an SSD (that I already use on another machine) leave any trace on the internal hard drive?

Honestly, I don't expect this to ever be a real issue, I doubt anyone will ever check or even care, but I just want to keep my work stuff entirely separate from my personal stuff. So if there's a fair chance I could muddy the two in any way by doing this, I won't - but it's my understanding that dual booting would be more or less adequately secure?